Add m-esr52 at 52.6.0

author: Matt A. Tobin <mattatobin@localhost.localdomain> 2018-02-02 04:16:08 -0500
committer: Matt A. Tobin <mattatobin@localhost.localdomain> 2018-02-02 04:16:08 -0500
commit: 5f8de423f190bbb79a62f804151bc24824fa32d8 (patch)
tree: 10027f336435511475e392454359edea8e25895d /gfx/src
parent: 49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff)
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51 files changed, 12233 insertions, 0 deletions
diff --git a/gfx/src/AppUnits.h b/gfx/src/AppUnits.h
new file mode 100644
index 000000000..e0ad6dc52
--- /dev/null
+++ b/gfx/src/AppUnits.h
@@ -0,0 +1,15 @@
+/* -*- Mode: C++; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_AppUnits_h
+#define mozilla_AppUnits_h
+
+#include <stdint.h>
+
+namespace mozilla {
+inline int32_t AppUnitsPerCSSPixel() { return 60; }
+inline int32_t AppUnitsPerCSSInch() { return 96 * AppUnitsPerCSSPixel(); }
+} // namespace mozilla
+#endif /* _NS_APPUNITS_H_ */
diff --git a/gfx/src/ArrayView.h b/gfx/src/ArrayView.h
new file mode 100644
index 000000000..3c6704f43
--- /dev/null
+++ b/gfx/src/ArrayView.h
@@ -0,0 +1,50 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef MOZILLA_GFX_ARRAY_VIEW_H_
+#define MOZILLA_GFX_ARRAY_VIEW_H_
+
+#include "nsTArray.h"
+
+/* This is similar to mfbt/Range.h but has implicit conversion
+ * from nsTArray and less bounds checking.
+ * For now, prefer Range over ArrayView */
+
+namespace mozilla {
+namespace gfx {
+
+template<typename T>
+class ArrayView
+{
+    public:
+        MOZ_IMPLICIT ArrayView(const nsTArray<T>& aData) :
+            mData(aData.Elements()), mLength(aData.Length())
+        {
+        }
+        ArrayView(const T* aData, const size_t aLength) :
+            mData(aData), mLength(aLength)
+        {
+        }
+        const T& operator[](const size_t aIdx) const
+        {
+            return mData[aIdx];
+        }
+        size_t Length() const
+        {
+            return mLength;
+        }
+        const T* Data() const
+        {
+            return mData;
+        }
+    private:
+        const T* mData;
+        const size_t mLength;
+};
+
+} // namespace gfx
+} // namespace mozilla
+
+#endif /* MOZILLA_GFX_ARRAY_VIEW_H_ */
diff --git a/gfx/src/DriverCrashGuard.cpp b/gfx/src/DriverCrashGuard.cpp
new file mode 100644
index 000000000..36d08dcf3
--- /dev/null
+++ b/gfx/src/DriverCrashGuard.cpp
@@ -0,0 +1,620 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#include "DriverCrashGuard.h"
+#include "gfxEnv.h"
+#include "gfxPrefs.h"
+#include "nsAppDirectoryServiceDefs.h"
+#include "nsDirectoryServiceUtils.h"
+#ifdef MOZ_CRASHREPORTER
+#include "nsExceptionHandler.h"
+#endif
+#include "nsServiceManagerUtils.h"
+#include "nsString.h"
+#include "nsXULAppAPI.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/Telemetry.h"
+#include "mozilla/Services.h"
+#include "mozilla/gfx/Logging.h"
+#include "mozilla/dom/ContentChild.h"
+
+namespace mozilla {
+namespace gfx {
+
+static const size_t NUM_CRASH_GUARD_TYPES = size_t(CrashGuardType::NUM_TYPES);
+static const char* sCrashGuardNames[] = {
+  "d3d11layers",
+  "d3d9video",
+  "glcontext",
+  "d3d11video",
+};
+static_assert(MOZ_ARRAY_LENGTH(sCrashGuardNames) == NUM_CRASH_GUARD_TYPES,
+              "CrashGuardType updated without a name string");
+
+static inline void
+BuildCrashGuardPrefName(CrashGuardType aType, nsCString& aOutPrefName)
+{
+  MOZ_ASSERT(aType < CrashGuardType::NUM_TYPES);
+  MOZ_ASSERT(sCrashGuardNames[size_t(aType)]);
+
+  aOutPrefName.Assign("gfx.crash-guard.status.");
+  aOutPrefName.Append(sCrashGuardNames[size_t(aType)]);
+}
+
+DriverCrashGuard::DriverCrashGuard(CrashGuardType aType, dom::ContentParent* aContentParent)
+ : mType(aType)
+ , mMode(aContentParent ? Mode::Proxy : Mode::Normal)
+ , mInitialized(false)
+ , mGuardActivated(false)
+ , mCrashDetected(false)
+{
+  BuildCrashGuardPrefName(aType, mStatusPref);
+}
+
+void
+DriverCrashGuard::InitializeIfNeeded()
+{
+  if (mInitialized) {
+    return;
+  }
+
+  mInitialized = true;
+  Initialize();
+}
+
+static inline bool
+AreCrashGuardsEnabled()
+{
+  // Crash guard isn't supported in the GPU process since the entire
+  // process is basically a crash guard.
+  if (XRE_IsGPUProcess()) {
+    return false;
+  }
+#ifdef NIGHTLY_BUILD
+  // We only use the crash guard on non-nightly channels, since the nightly
+  // channel is for development and having graphics features perma-disabled
+  // is rather annoying.  Unless the user forces is with an environment
+  // variable, which comes in handy for testing.
+  return gfxEnv::ForceCrashGuardNightly();
+#else
+  // Check to see if all guards have been disabled through the environment.
+  if (gfxEnv::DisableCrashGuard()) {
+    return false;
+  }
+  return true;
+#endif
+}
+
+void
+DriverCrashGuard::Initialize()
+{
+  if (!AreCrashGuardsEnabled()) {
+    return;
+  }
+
+  // Using DriverCrashGuard off the main thread currently does not work. Under
+  // e10s it could conceivably work by dispatching the IPC calls via the main
+  // thread. In the parent process this would be harder. For now, we simply
+  // exit early instead.
+  if (!NS_IsMainThread()) {
+    return;
+  }
+
+  mGfxInfo = services::GetGfxInfo();
+
+  if (XRE_IsContentProcess()) {
+    // Ask the parent whether or not activating the guard is okay. The parent
+    // won't bother if it detected a crash.
+    dom::ContentChild* cc = dom::ContentChild::GetSingleton();
+    cc->SendBeginDriverCrashGuard(uint32_t(mType), &mCrashDetected);
+    if (mCrashDetected) {
+      LogFeatureDisabled();
+      return;
+    }
+
+    ActivateGuard();
+    return;
+  }
+
+  // Always check whether or not the lock file exists. For example, we could
+  // have crashed creating a D3D9 device in the parent process, and on restart
+  // are now requesting one in the child process. We catch everything here.
+  if (RecoverFromCrash()) {
+    mCrashDetected = true;
+    return;
+  }
+
+  // If the environment has changed, we always activate the guard. In the
+  // parent process this performs main-thread disk I/O. Child process guards
+  // only incur an IPC cost, so if we're proxying for a child process, we
+  // play it safe and activate the guard as long as we don't expect it to
+  // crash.
+  if (CheckOrRefreshEnvironment() ||
+      (mMode == Mode::Proxy && GetStatus() != DriverInitStatus::Crashed))
+  {
+    ActivateGuard();
+    return;
+  }
+
+  // If we got here and our status is "crashed", then the environment has not
+  // updated and we do not want to attempt to use the driver again.
+  if (GetStatus() == DriverInitStatus::Crashed) {
+    mCrashDetected = true;
+    LogFeatureDisabled();
+  }
+}
+
+DriverCrashGuard::~DriverCrashGuard()
+{
+  if (!mGuardActivated) {
+    return;
+  }
+
+  if (XRE_IsParentProcess()) {
+    if (mGuardFile) {
+      mGuardFile->Remove(false);
+    }
+
+    // If during our initialization, no other process encountered a crash, we
+    // proceed to mark the status as okay.
+    if (GetStatus() != DriverInitStatus::Crashed) {
+      SetStatus(DriverInitStatus::Okay);
+    }
+  } else {
+    dom::ContentChild::GetSingleton()->SendEndDriverCrashGuard(uint32_t(mType));
+  }
+
+#ifdef MOZ_CRASHREPORTER
+  // Remove the crash report annotation.
+  CrashReporter::AnnotateCrashReport(NS_LITERAL_CSTRING("GraphicsStartupTest"),
+                                     NS_LITERAL_CSTRING(""));
+#endif
+}
+
+bool
+DriverCrashGuard::Crashed()
+{
+  InitializeIfNeeded();
+
+  // Note, we read mCrashDetected instead of GetStatus(), since in child
+  // processes we're not guaranteed that the prefs have been synced in
+  // time.
+  return mCrashDetected;
+}
+
+nsCOMPtr<nsIFile>
+DriverCrashGuard::GetGuardFile()
+{
+  MOZ_ASSERT(XRE_IsParentProcess());
+
+  nsCString filename;
+  filename.Assign(sCrashGuardNames[size_t(mType)]);
+  filename.Append(".guard");
+
+  nsCOMPtr<nsIFile> file;
+  NS_GetSpecialDirectory(NS_APP_USER_PROFILE_LOCAL_50_DIR, getter_AddRefs(file));
+  if (!file) {
+    return nullptr;
+  }
+  if (!NS_SUCCEEDED(file->AppendNative(filename))) {
+    return nullptr;
+  }
+  return file;
+}
+
+void
+DriverCrashGuard::ActivateGuard()
+{
+  mGuardActivated = true;
+
+#ifdef MOZ_CRASHREPORTER
+  // Anotate crash reports only if we're a real guard. Otherwise, we could
+  // attribute a random parent process crash to a graphics problem in a child
+  // process.
+  if (mMode != Mode::Proxy) {
+    CrashReporter::AnnotateCrashReport(NS_LITERAL_CSTRING("GraphicsStartupTest"),
+                                       NS_LITERAL_CSTRING("1"));
+  }
+#endif
+
+  // If we're in the content process, the rest of the guarding is handled
+  // in the parent.
+  if (XRE_IsContentProcess()) {
+    return;
+  }
+
+  SetStatus(DriverInitStatus::Attempting);
+
+  if (mMode != Mode::Proxy) {
+    // In parent process guards, we use two tombstones to detect crashes: a
+    // preferences and a zero-byte file on the filesystem.
+    FlushPreferences();
+
+    // Create a temporary tombstone/lockfile.
+    FILE* fp = nullptr;
+    mGuardFile = GetGuardFile();
+    if (!mGuardFile || !NS_SUCCEEDED(mGuardFile->OpenANSIFileDesc("w", &fp))) {
+      return;
+    }
+    fclose(fp);
+  }
+}
+
+void
+DriverCrashGuard::NotifyCrashed()
+{
+  CheckOrRefreshEnvironment();
+  SetStatus(DriverInitStatus::Crashed);
+  FlushPreferences();
+  LogCrashRecovery();
+}
+
+bool
+DriverCrashGuard::RecoverFromCrash()
+{
+  MOZ_ASSERT(XRE_IsParentProcess());
+
+  nsCOMPtr<nsIFile> file = GetGuardFile();
+  bool exists;
+  if ((file &&
+       NS_SUCCEEDED(file->Exists(&exists)) &&
+       exists) ||
+      (GetStatus() == DriverInitStatus::Attempting))
+  {
+    // If we get here, we've just recovered from a crash. Disable acceleration
+    // until the environment changes.
+    if (file) {
+      file->Remove(false);
+    }
+    NotifyCrashed();
+    return true;
+  }
+  return false;
+}
+
+// Return true if the caller should proceed to guard for crashes. False if
+// the environment has not changed. We persist the "changed" status across
+// calls, so that after an environment changes, all guards for the new
+// session are activated rather than just the first.
+bool
+DriverCrashGuard::CheckOrRefreshEnvironment()
+{
+  // Our result can be cached statically since we don't check live prefs.
+  static bool sBaseInfoChanged = false;
+  static bool sBaseInfoChecked = false;
+
+  if (!sBaseInfoChecked) {
+    // None of the prefs we care about, so we cache the result statically.
+    sBaseInfoChecked = true;
+    sBaseInfoChanged = UpdateBaseEnvironment();
+  }
+
+  // Always update the full environment, even if the base info didn't change.
+  return UpdateEnvironment() ||
+         sBaseInfoChanged ||
+         GetStatus() == DriverInitStatus::Unknown;
+}
+
+bool
+DriverCrashGuard::UpdateBaseEnvironment()
+{
+  bool changed = false;
+  if (mGfxInfo) {
+    nsString value;
+
+    // Driver properties.
+    mGfxInfo->GetAdapterDriverVersion(value);
+    changed |= CheckAndUpdatePref("driverVersion", value);
+    mGfxInfo->GetAdapterDeviceID(value);
+    changed |= CheckAndUpdatePref("deviceID", value);
+  }
+
+  // Firefox properties.
+  changed |= CheckAndUpdatePref("appVersion", NS_LITERAL_STRING(MOZ_APP_VERSION));
+
+  return changed;
+}
+
+bool
+DriverCrashGuard::FeatureEnabled(int aFeature, bool aDefault)
+{
+  if (!mGfxInfo) {
+    return aDefault;
+  }
+  int32_t status;
+  nsCString discardFailureId;
+  if (!NS_SUCCEEDED(mGfxInfo->GetFeatureStatus(aFeature, discardFailureId, &status))) {
+    return false;
+  }
+  return status == nsIGfxInfo::FEATURE_STATUS_OK;
+}
+
+bool
+DriverCrashGuard::CheckAndUpdateBoolPref(const char* aPrefName, bool aCurrentValue)
+{
+  std::string pref = GetFullPrefName(aPrefName);
+
+  bool oldValue;
+  if (NS_SUCCEEDED(Preferences::GetBool(pref.c_str(), &oldValue)) &&
+      oldValue == aCurrentValue)
+  {
+    return false;
+  }
+  Preferences::SetBool(pref.c_str(), aCurrentValue);
+  return true;
+}
+
+bool
+DriverCrashGuard::CheckAndUpdatePref(const char* aPrefName, const nsAString& aCurrentValue)
+{
+  std::string pref = GetFullPrefName(aPrefName);
+
+  nsAdoptingString oldValue = Preferences::GetString(pref.c_str());
+  if (oldValue == aCurrentValue) {
+    return false;
+  }
+  Preferences::SetString(pref.c_str(), aCurrentValue);
+  return true;
+}
+
+std::string
+DriverCrashGuard::GetFullPrefName(const char* aPref)
+{
+  return std::string("gfx.crash-guard.") +
+         std::string(sCrashGuardNames[uint32_t(mType)]) +
+         std::string(".") +
+         std::string(aPref);
+}
+
+DriverInitStatus
+DriverCrashGuard::GetStatus() const
+{
+  return (DriverInitStatus)Preferences::GetInt(mStatusPref.get(), 0);
+}
+
+void
+DriverCrashGuard::SetStatus(DriverInitStatus aStatus)
+{
+  MOZ_ASSERT(XRE_IsParentProcess());
+
+  Preferences::SetInt(mStatusPref.get(), int32_t(aStatus));
+}
+
+void
+DriverCrashGuard::FlushPreferences()
+{
+  MOZ_ASSERT(XRE_IsParentProcess());
+
+  if (nsIPrefService* prefService = Preferences::GetService()) {
+    prefService->SavePrefFile(nullptr);
+  }
+}
+
+void
+DriverCrashGuard::ForEachActiveCrashGuard(const CrashGuardCallback& aCallback)
+{
+  if (!AreCrashGuardsEnabled()) {
+    // Even if guards look active (via prefs), they can be ignored if globally
+    // disabled.
+    return;
+  }
+
+  for (size_t i = 0; i < NUM_CRASH_GUARD_TYPES; i++) {
+    CrashGuardType type = static_cast<CrashGuardType>(i);
+
+    nsCString prefName;
+    BuildCrashGuardPrefName(type, prefName);
+
+    auto status =
+      static_cast<DriverInitStatus>(Preferences::GetInt(prefName.get(), 0));
+    if (status != DriverInitStatus::Crashed) {
+      continue;
+    }
+
+    aCallback(sCrashGuardNames[i], prefName.get());
+  }
+}
+
+D3D11LayersCrashGuard::D3D11LayersCrashGuard(dom::ContentParent* aContentParent)
+ : DriverCrashGuard(CrashGuardType::D3D11Layers, aContentParent)
+{
+}
+
+void
+D3D11LayersCrashGuard::Initialize()
+{
+  if (!XRE_IsParentProcess()) {
+    // We assume the parent process already performed crash detection for
+    // graphics devices.
+    return;
+  }
+
+  DriverCrashGuard::Initialize();
+
+  // If no telemetry states have been recorded, this will set the state to okay.
+  // Otherwise, it will have no effect.
+  RecordTelemetry(TelemetryState::Okay);
+}
+
+bool
+D3D11LayersCrashGuard::UpdateEnvironment()
+{
+  // Our result can be cached statically since we don't check live prefs.
+  static bool checked = false;
+  static bool changed = false;
+
+  if (checked) {
+    return changed;
+  }
+
+  checked = true;
+
+  // Feature status.
+#if defined(XP_WIN)
+  bool d2dEnabled = gfxPrefs::Direct2DForceEnabled() ||
+                    (!gfxPrefs::Direct2DDisabled() && FeatureEnabled(nsIGfxInfo::FEATURE_DIRECT2D));
+  changed |= CheckAndUpdateBoolPref("feature-d2d", d2dEnabled);
+
+  bool d3d11Enabled = !gfxPrefs::LayersPreferD3D9();
+  if (!FeatureEnabled(nsIGfxInfo::FEATURE_DIRECT3D_11_LAYERS)) {
+    d3d11Enabled = false;
+  }
+  changed |= CheckAndUpdateBoolPref("feature-d3d11", d3d11Enabled);
+#endif
+
+  if (!changed) {
+    return false;
+  }
+
+  RecordTelemetry(TelemetryState::EnvironmentChanged);
+  return true;
+}
+
+void
+D3D11LayersCrashGuard::LogCrashRecovery()
+{
+  RecordTelemetry(TelemetryState::RecoveredFromCrash);
+  gfxCriticalNote << "D3D11 layers just crashed; D3D11 will be disabled.";
+}
+
+void
+D3D11LayersCrashGuard::LogFeatureDisabled()
+{
+  RecordTelemetry(TelemetryState::FeatureDisabled);
+  gfxCriticalNote << "D3D11 layers disabled due to a prior crash.";
+}
+
+void
+D3D11LayersCrashGuard::RecordTelemetry(TelemetryState aState)
+{
+  // D3D11LayersCrashGuard is a no-op in the child process.
+  if (!XRE_IsParentProcess()) {
+    return;
+  }
+
+  // Since we instantiate this class more than once, make sure we only record
+  // the first state (since that is really all we care about).
+  static bool sTelemetryStateRecorded = false;
+  if (sTelemetryStateRecorded) {
+    return;
+  }
+
+  Telemetry::Accumulate(Telemetry::GRAPHICS_DRIVER_STARTUP_TEST, int32_t(aState));
+  sTelemetryStateRecorded = true;
+}
+
+D3D9VideoCrashGuard::D3D9VideoCrashGuard(dom::ContentParent* aContentParent)
+ : DriverCrashGuard(CrashGuardType::D3D9Video, aContentParent)
+{
+}
+
+bool
+D3D9VideoCrashGuard::UpdateEnvironment()
+{
+  // We don't care about any extra preferences here.
+  return false;
+}
+
+void
+D3D9VideoCrashGuard::LogCrashRecovery()
+{
+  gfxCriticalNote << "DXVA2D3D9 just crashed; hardware video will be disabled.";
+}
+
+void
+D3D9VideoCrashGuard::LogFeatureDisabled()
+{
+  gfxCriticalNote << "DXVA2D3D9 video decoding is disabled due to a previous crash.";
+}
+
+D3D11VideoCrashGuard::D3D11VideoCrashGuard(dom::ContentParent* aContentParent)
+ : DriverCrashGuard(CrashGuardType::D3D11Video, aContentParent)
+{
+}
+
+bool
+D3D11VideoCrashGuard::UpdateEnvironment()
+{
+  // We don't care about any extra preferences here.
+  return false;
+}
+
+void
+D3D11VideoCrashGuard::LogCrashRecovery()
+{
+  gfxCriticalNote << "DXVA2D3D11 just crashed; hardware video will be disabled.";
+}
+
+void
+D3D11VideoCrashGuard::LogFeatureDisabled()
+{
+  gfxCriticalNote << "DXVA2D3D11 video decoding is disabled due to a previous crash.";
+}
+
+GLContextCrashGuard::GLContextCrashGuard(dom::ContentParent* aContentParent)
+ : DriverCrashGuard(CrashGuardType::GLContext, aContentParent)
+{
+}
+
+void
+GLContextCrashGuard::Initialize()
+{
+  if (XRE_IsContentProcess()) {
+    // Disable the GL crash guard in content processes, since we're not going
+    // to lose the entire browser and we don't want to hinder WebGL availability.
+    return;
+  }
+
+#if defined(MOZ_WIDGET_ANDROID)
+  // Disable the WebGL crash guard on Android - it doesn't use E10S, and
+  // its drivers will essentially never change, so the crash guard could
+  // permanently disable WebGL.
+  return;
+#endif
+
+  DriverCrashGuard::Initialize();
+}
+
+bool
+GLContextCrashGuard::UpdateEnvironment()
+{
+  static bool checked = false;
+  static bool changed = false;
+
+  if (checked) {
+    return changed;
+  }
+
+  checked = true;
+
+#if defined(XP_WIN)
+  changed |= CheckAndUpdateBoolPref("gfx.driver-init.webgl-angle-force-d3d11",
+                                    gfxPrefs::WebGLANGLEForceD3D11());
+  changed |= CheckAndUpdateBoolPref("gfx.driver-init.webgl-angle-try-d3d11",
+                                    gfxPrefs::WebGLANGLETryD3D11());
+  changed |= CheckAndUpdateBoolPref("gfx.driver-init.webgl-angle-force-warp",
+                                    gfxPrefs::WebGLANGLEForceWARP());
+  changed |= CheckAndUpdateBoolPref("gfx.driver-init.webgl-angle",
+                                    FeatureEnabled(nsIGfxInfo::FEATURE_WEBGL_ANGLE, false));
+  changed |= CheckAndUpdateBoolPref("gfx.driver-init.direct3d11-angle",
+                                    FeatureEnabled(nsIGfxInfo::FEATURE_DIRECT3D_11_ANGLE, false));
+#endif
+
+  return changed;
+}
+
+void
+GLContextCrashGuard::LogCrashRecovery()
+{
+  gfxCriticalNote << "GLContext just crashed.";
+}
+
+void
+GLContextCrashGuard::LogFeatureDisabled()
+{
+  gfxCriticalNote << "GLContext remains enabled despite a previous crash.";
+}
+
+} // namespace gfx
+} // namespace mozilla
diff --git a/gfx/src/DriverCrashGuard.h b/gfx/src/DriverCrashGuard.h
new file mode 100644
index 000000000..9a0c5851a
--- /dev/null
+++ b/gfx/src/DriverCrashGuard.h
@@ -0,0 +1,182 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#ifndef gfx_src_DriverCrashGuard_h__
+#define gfx_src_DriverCrashGuard_h__
+
+#include "nsCOMPtr.h"
+#include "nsIGfxInfo.h"
+#include "nsIFile.h"
+#include "nsString.h"
+#include "mozilla/Function.h"
+#include <string>
+
+namespace mozilla {
+
+namespace dom {
+class ContentParent;
+} // namespace dom
+
+namespace gfx {
+
+enum class DriverInitStatus
+{
+  // Drivers have not been initialized yet.
+  Unknown,
+
+  // We're attempting to initialize drivers.
+  Attempting,
+
+  // Drivers were successfully initialized last run.
+  Okay,
+
+  // We crashed during driver initialization, and have restarted.
+  Crashed
+};
+
+enum class CrashGuardType : uint32_t
+{
+  D3D11Layers,
+  D3D9Video,
+  GLContext,
+  D3D11Video,
+  // Add new entries above this line, update the name array in
+  // DriverCrashGuard.cpp, and make sure to add an entry in
+  // ContentParent.cpp.
+
+  NUM_TYPES
+};
+
+// DriverCrashGuard is used to detect crashes at graphics driver callsites.
+// 
+// If the graphics environment is unrecognized or has changed since the last
+// session, the crash guard will activate and will detect any crashes within
+// the scope of the guard object.
+//
+// If a callsite has a previously encountered crash, and the environment has
+// not changed since the last session, then the guard will set a status flag
+// indicating that the driver should not be used.
+class DriverCrashGuard
+{
+public:
+  DriverCrashGuard(CrashGuardType aType, dom::ContentParent* aContentParent);
+  virtual ~DriverCrashGuard();
+
+  bool Crashed();
+  void NotifyCrashed();
+
+  // These are the values reported to Telemetry (GRAPHICS_DRIVER_STARTUP_TEST).
+  // Values should not change; add new values to the end.
+  enum class TelemetryState {
+    Okay = 0,
+    EnvironmentChanged = 1,
+    RecoveredFromCrash = 2,
+    FeatureDisabled = 3
+  };
+
+  enum class Mode {
+    // Normal operation.
+    Normal,
+
+    // Acting as a proxy between the parent and child process.
+    Proxy
+  };
+
+  typedef mozilla::function<void(const char* aName, const char* aPrefName)>
+    CrashGuardCallback;
+  static void ForEachActiveCrashGuard(const CrashGuardCallback& aCallback);
+
+protected:
+  virtual void Initialize();
+  virtual bool UpdateEnvironment() = 0;
+  virtual void LogCrashRecovery() = 0;
+  virtual void LogFeatureDisabled() = 0;
+
+  // Helper functions.
+  bool FeatureEnabled(int aFeature, bool aDefault=true);
+  bool CheckAndUpdatePref(const char* aPrefName, const nsAString& aCurrentValue);
+  bool CheckAndUpdateBoolPref(const char* aPrefName, bool aCurrentValue);
+  std::string GetFullPrefName(const char* aPref);
+
+private:
+  // Either process.
+  void InitializeIfNeeded();
+  bool CheckOrRefreshEnvironment();
+  bool UpdateBaseEnvironment();
+  DriverInitStatus GetStatus() const;
+
+  // Parent process only.
+  nsCOMPtr<nsIFile> GetGuardFile();
+  bool RecoverFromCrash();
+  void ActivateGuard();
+  void FlushPreferences();
+  void SetStatus(DriverInitStatus aStatus);
+
+private:
+  CrashGuardType mType;
+  Mode mMode;
+  bool mInitialized;
+  bool mGuardActivated;
+  bool mCrashDetected;
+  nsCOMPtr<nsIFile> mGuardFile;
+
+protected:
+  nsCString mStatusPref;
+  nsCOMPtr<nsIGfxInfo> mGfxInfo;
+};
+
+class D3D11LayersCrashGuard final : public DriverCrashGuard
+{
+ public:
+  explicit D3D11LayersCrashGuard(dom::ContentParent* aContentParent = nullptr);
+
+ protected:
+  void Initialize() override;
+  bool UpdateEnvironment() override;
+  void LogCrashRecovery() override;
+  void LogFeatureDisabled() override;
+
+ private:
+  void RecordTelemetry(TelemetryState aState);
+};
+
+class D3D9VideoCrashGuard final : public DriverCrashGuard
+{
+ public:
+  explicit D3D9VideoCrashGuard(dom::ContentParent* aContentParent = nullptr);
+
+ protected:
+  bool UpdateEnvironment() override;
+  void LogCrashRecovery() override;
+  void LogFeatureDisabled() override;
+};
+
+class D3D11VideoCrashGuard final : public DriverCrashGuard
+{
+ public:
+  explicit D3D11VideoCrashGuard(dom::ContentParent* aContentParent = nullptr);
+
+ protected:
+  bool UpdateEnvironment() override;
+  void LogCrashRecovery() override;
+  void LogFeatureDisabled() override;
+};
+
+class GLContextCrashGuard final : public DriverCrashGuard
+{
+ public:
+  explicit GLContextCrashGuard(dom::ContentParent* aContentParent = nullptr);
+  void Initialize() override;
+
+ protected:
+  bool UpdateEnvironment() override;
+  void LogCrashRecovery() override;
+  void LogFeatureDisabled() override;
+};
+
+} // namespace gfx
+} // namespace mozilla
+
+#endif // gfx_src_DriverCrashGuard_h__
+
diff --git a/gfx/src/FilterSupport.cpp b/gfx/src/FilterSupport.cpp
new file mode 100644
index 000000000..fed7b6879
--- /dev/null
+++ b/gfx/src/FilterSupport.cpp
@@ -0,0 +1,2185 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "FilterSupport.h"
+
+#include "mozilla/gfx/2D.h"
+#include "mozilla/gfx/Filters.h"
+#include "mozilla/gfx/Logging.h"
+#include "mozilla/PodOperations.h"
+
+#include "gfxContext.h"
+#include "gfxPattern.h"
+#include "gfxPlatform.h"
+#include "gfx2DGlue.h"
+
+#include "nsMargin.h"
+
+// c = n / 255
+// c <= 0.0031308f ? c * 12.92f : 1.055f * powf(c, 1 / 2.4f) - 0.055f
+static const float glinearRGBTosRGBMap[256] = {
+  0.000f, 0.050f, 0.085f, 0.111f, 0.132f, 0.150f, 0.166f, 0.181f,
+  0.194f, 0.207f, 0.219f, 0.230f, 0.240f, 0.250f, 0.260f, 0.269f,
+  0.278f, 0.286f, 0.295f, 0.303f, 0.310f, 0.318f, 0.325f, 0.332f,
+  0.339f, 0.346f, 0.352f, 0.359f, 0.365f, 0.371f, 0.378f, 0.383f,
+  0.389f, 0.395f, 0.401f, 0.406f, 0.412f, 0.417f, 0.422f, 0.427f,
+  0.433f, 0.438f, 0.443f, 0.448f, 0.452f, 0.457f, 0.462f, 0.466f,
+  0.471f, 0.476f, 0.480f, 0.485f, 0.489f, 0.493f, 0.498f, 0.502f,
+  0.506f, 0.510f, 0.514f, 0.518f, 0.522f, 0.526f, 0.530f, 0.534f,
+  0.538f, 0.542f, 0.546f, 0.549f, 0.553f, 0.557f, 0.561f, 0.564f,
+  0.568f, 0.571f, 0.575f, 0.579f, 0.582f, 0.586f, 0.589f, 0.592f,
+  0.596f, 0.599f, 0.603f, 0.606f, 0.609f, 0.613f, 0.616f, 0.619f,
+  0.622f, 0.625f, 0.629f, 0.632f, 0.635f, 0.638f, 0.641f, 0.644f,
+  0.647f, 0.650f, 0.653f, 0.656f, 0.659f, 0.662f, 0.665f, 0.668f,
+  0.671f, 0.674f, 0.677f, 0.680f, 0.683f, 0.685f, 0.688f, 0.691f,
+  0.694f, 0.697f, 0.699f, 0.702f, 0.705f, 0.708f, 0.710f, 0.713f,
+  0.716f, 0.718f, 0.721f, 0.724f, 0.726f, 0.729f, 0.731f, 0.734f,
+  0.737f, 0.739f, 0.742f, 0.744f, 0.747f, 0.749f, 0.752f, 0.754f,
+  0.757f, 0.759f, 0.762f, 0.764f, 0.767f, 0.769f, 0.772f, 0.774f,
+  0.776f, 0.779f, 0.781f, 0.784f, 0.786f, 0.788f, 0.791f, 0.793f,
+  0.795f, 0.798f, 0.800f, 0.802f, 0.805f, 0.807f, 0.809f, 0.812f,
+  0.814f, 0.816f, 0.818f, 0.821f, 0.823f, 0.825f, 0.827f, 0.829f,
+  0.832f, 0.834f, 0.836f, 0.838f, 0.840f, 0.843f, 0.845f, 0.847f,
+  0.849f, 0.851f, 0.853f, 0.855f, 0.857f, 0.860f, 0.862f, 0.864f,
+  0.866f, 0.868f, 0.870f, 0.872f, 0.874f, 0.876f, 0.878f, 0.880f,
+  0.882f, 0.884f, 0.886f, 0.888f, 0.890f, 0.892f, 0.894f, 0.896f,
+  0.898f, 0.900f, 0.902f, 0.904f, 0.906f, 0.908f, 0.910f, 0.912f,
+  0.914f, 0.916f, 0.918f, 0.920f, 0.922f, 0.924f, 0.926f, 0.928f,
+  0.930f, 0.931f, 0.933f, 0.935f, 0.937f, 0.939f, 0.941f, 0.943f,
+  0.945f, 0.946f, 0.948f, 0.950f, 0.952f, 0.954f, 0.956f, 0.957f,
+  0.959f, 0.961f, 0.963f, 0.965f, 0.967f, 0.968f, 0.970f, 0.972f,
+  0.974f, 0.975f, 0.977f, 0.979f, 0.981f, 0.983f, 0.984f, 0.986f,
+  0.988f, 0.990f, 0.991f, 0.993f, 0.995f, 0.997f, 0.998f, 1.000f
+};
+
+// c = n / 255
+// c <= 0.04045f ? c / 12.92f : powf((c + 0.055f) / 1.055f, 2.4f)
+static const float gsRGBToLinearRGBMap[256] = {
+  0.000f, 0.000f, 0.001f, 0.001f, 0.001f, 0.002f, 0.002f, 0.002f,
+  0.002f, 0.003f, 0.003f, 0.003f, 0.004f, 0.004f, 0.004f, 0.005f,
+  0.005f, 0.006f, 0.006f, 0.007f, 0.007f, 0.007f, 0.008f, 0.009f,
+  0.009f, 0.010f, 0.010f, 0.011f, 0.012f, 0.012f, 0.013f, 0.014f,
+  0.014f, 0.015f, 0.016f, 0.017f, 0.018f, 0.019f, 0.019f, 0.020f,
+  0.021f, 0.022f, 0.023f, 0.024f, 0.025f, 0.026f, 0.027f, 0.028f,
+  0.030f, 0.031f, 0.032f, 0.033f, 0.034f, 0.036f, 0.037f, 0.038f,
+  0.040f, 0.041f, 0.042f, 0.044f, 0.045f, 0.047f, 0.048f, 0.050f,
+  0.051f, 0.053f, 0.054f, 0.056f, 0.058f, 0.060f, 0.061f, 0.063f,
+  0.065f, 0.067f, 0.068f, 0.070f, 0.072f, 0.074f, 0.076f, 0.078f,
+  0.080f, 0.082f, 0.084f, 0.087f, 0.089f, 0.091f, 0.093f, 0.095f,
+  0.098f, 0.100f, 0.102f, 0.105f, 0.107f, 0.109f, 0.112f, 0.114f,
+  0.117f, 0.120f, 0.122f, 0.125f, 0.127f, 0.130f, 0.133f, 0.136f,
+  0.138f, 0.141f, 0.144f, 0.147f, 0.150f, 0.153f, 0.156f, 0.159f,
+  0.162f, 0.165f, 0.168f, 0.171f, 0.175f, 0.178f, 0.181f, 0.184f,
+  0.188f, 0.191f, 0.195f, 0.198f, 0.202f, 0.205f, 0.209f, 0.212f,
+  0.216f, 0.220f, 0.223f, 0.227f, 0.231f, 0.235f, 0.238f, 0.242f,
+  0.246f, 0.250f, 0.254f, 0.258f, 0.262f, 0.266f, 0.270f, 0.275f,
+  0.279f, 0.283f, 0.287f, 0.292f, 0.296f, 0.301f, 0.305f, 0.309f,
+  0.314f, 0.319f, 0.323f, 0.328f, 0.332f, 0.337f, 0.342f, 0.347f,
+  0.352f, 0.356f, 0.361f, 0.366f, 0.371f, 0.376f, 0.381f, 0.386f,
+  0.392f, 0.397f, 0.402f, 0.407f, 0.413f, 0.418f, 0.423f, 0.429f,
+  0.434f, 0.440f, 0.445f, 0.451f, 0.456f, 0.462f, 0.468f, 0.474f,
+  0.479f, 0.485f, 0.491f, 0.497f, 0.503f, 0.509f, 0.515f, 0.521f,
+  0.527f, 0.533f, 0.539f, 0.546f, 0.552f, 0.558f, 0.565f, 0.571f,
+  0.578f, 0.584f, 0.591f, 0.597f, 0.604f, 0.610f, 0.617f, 0.624f,
+  0.631f, 0.638f, 0.644f, 0.651f, 0.658f, 0.665f, 0.672f, 0.680f,
+  0.687f, 0.694f, 0.701f, 0.708f, 0.716f, 0.723f, 0.730f, 0.738f,
+  0.745f, 0.753f, 0.761f, 0.768f, 0.776f, 0.784f, 0.791f, 0.799f,
+  0.807f, 0.815f, 0.823f, 0.831f, 0.839f, 0.847f, 0.855f, 0.863f,
+  0.871f, 0.880f, 0.888f, 0.896f, 0.905f, 0.913f, 0.922f, 0.930f,
+  0.939f, 0.947f, 0.956f, 0.965f, 0.973f, 0.982f, 0.991f, 1.000f
+};
+
+namespace mozilla {
+namespace gfx {
+
+// Some convenience FilterNode creation functions.
+
+namespace FilterWrappers {
+
+  static already_AddRefed<FilterNode>
+  Unpremultiply(DrawTarget* aDT, FilterNode* aInput)
+  {
+    RefPtr<FilterNode> filter = aDT->CreateFilter(FilterType::UNPREMULTIPLY);
+    if (filter) {
+      filter->SetInput(IN_UNPREMULTIPLY_IN, aInput);
+      return filter.forget();
+    }
+    return nullptr;
+  }
+
+  static already_AddRefed<FilterNode>
+  Premultiply(DrawTarget* aDT, FilterNode* aInput)
+  {
+    RefPtr<FilterNode> filter = aDT->CreateFilter(FilterType::PREMULTIPLY);
+    if (filter) {
+      filter->SetInput(IN_PREMULTIPLY_IN, aInput);
+      return filter.forget();
+    }
+    return nullptr;
+  }
+
+  static already_AddRefed<FilterNode>
+  LinearRGBToSRGB(DrawTarget* aDT, FilterNode* aInput)
+  {
+    RefPtr<FilterNode> transfer = aDT->CreateFilter(FilterType::DISCRETE_TRANSFER);
+    if (transfer) {
+      transfer->SetAttribute(ATT_DISCRETE_TRANSFER_DISABLE_R, false);
+      transfer->SetAttribute(ATT_DISCRETE_TRANSFER_TABLE_R, glinearRGBTosRGBMap, 256);
+      transfer->SetAttribute(ATT_DISCRETE_TRANSFER_DISABLE_G, false);
+      transfer->SetAttribute(ATT_DISCRETE_TRANSFER_TABLE_G, glinearRGBTosRGBMap, 256);
+      transfer->SetAttribute(ATT_DISCRETE_TRANSFER_DISABLE_B, false);
+      transfer->SetAttribute(ATT_DISCRETE_TRANSFER_TABLE_B, glinearRGBTosRGBMap, 256);
+      transfer->SetAttribute(ATT_DISCRETE_TRANSFER_DISABLE_A, true);
+      transfer->SetInput(IN_DISCRETE_TRANSFER_IN, aInput);
+      return transfer.forget();
+    }
+    return nullptr;
+  }
+
+  static already_AddRefed<FilterNode>
+  SRGBToLinearRGB(DrawTarget* aDT, FilterNode* aInput)
+  {
+    RefPtr<FilterNode> transfer = aDT->CreateFilter(FilterType::DISCRETE_TRANSFER);
+    if (transfer) {
+      transfer->SetAttribute(ATT_DISCRETE_TRANSFER_DISABLE_R, false);
+      transfer->SetAttribute(ATT_DISCRETE_TRANSFER_TABLE_R, gsRGBToLinearRGBMap, 256);
+      transfer->SetAttribute(ATT_DISCRETE_TRANSFER_DISABLE_G, false);
+      transfer->SetAttribute(ATT_DISCRETE_TRANSFER_TABLE_G, gsRGBToLinearRGBMap, 256);
+      transfer->SetAttribute(ATT_DISCRETE_TRANSFER_DISABLE_B, false);
+      transfer->SetAttribute(ATT_DISCRETE_TRANSFER_TABLE_B, gsRGBToLinearRGBMap, 256);
+      transfer->SetAttribute(ATT_DISCRETE_TRANSFER_DISABLE_A, true);
+      transfer->SetInput(IN_DISCRETE_TRANSFER_IN, aInput);
+      return transfer.forget();
+    }
+    return nullptr;
+  }
+
+  static already_AddRefed<FilterNode>
+  Crop(DrawTarget* aDT, FilterNode* aInputFilter, const IntRect& aRect)
+  {
+    RefPtr<FilterNode> filter = aDT->CreateFilter(FilterType::CROP);
+    if (filter) {
+      filter->SetAttribute(ATT_CROP_RECT, Rect(aRect));
+      filter->SetInput(IN_CROP_IN, aInputFilter);
+      return filter.forget();
+    }
+    return nullptr;
+  }
+
+  static already_AddRefed<FilterNode>
+  Offset(DrawTarget* aDT, FilterNode* aInputFilter, const IntPoint& aOffset)
+  {
+    RefPtr<FilterNode> filter = aDT->CreateFilter(FilterType::TRANSFORM);
+    if (filter) {
+      filter->SetAttribute(ATT_TRANSFORM_MATRIX, Matrix::Translation(aOffset.x, aOffset.y));
+      filter->SetInput(IN_TRANSFORM_IN, aInputFilter);
+      return filter.forget();
+    }
+    return nullptr;
+  }
+
+  static already_AddRefed<FilterNode>
+  GaussianBlur(DrawTarget* aDT, FilterNode* aInputFilter, const Size& aStdDeviation)
+  {
+    float stdX = float(std::min(aStdDeviation.width, kMaxStdDeviation));
+    float stdY = float(std::min(aStdDeviation.height, kMaxStdDeviation));
+    if (stdX == stdY) {
+      RefPtr<FilterNode> filter = aDT->CreateFilter(FilterType::GAUSSIAN_BLUR);
+      if (filter) {
+        filter->SetAttribute(ATT_GAUSSIAN_BLUR_STD_DEVIATION, stdX);
+        filter->SetInput(IN_GAUSSIAN_BLUR_IN, aInputFilter);
+        return filter.forget();
+      }
+      return nullptr;
+    }
+    RefPtr<FilterNode> filterH = aDT->CreateFilter(FilterType::DIRECTIONAL_BLUR);
+    RefPtr<FilterNode> filterV = aDT->CreateFilter(FilterType::DIRECTIONAL_BLUR);
+    if (filterH && filterV) {
+      filterH->SetAttribute(ATT_DIRECTIONAL_BLUR_DIRECTION, (uint32_t)BLUR_DIRECTION_X);
+      filterH->SetAttribute(ATT_DIRECTIONAL_BLUR_STD_DEVIATION, stdX);
+      filterV->SetAttribute(ATT_DIRECTIONAL_BLUR_DIRECTION, (uint32_t)BLUR_DIRECTION_Y);
+      filterV->SetAttribute(ATT_DIRECTIONAL_BLUR_STD_DEVIATION, stdY);
+      filterH->SetInput(IN_DIRECTIONAL_BLUR_IN, aInputFilter);
+      filterV->SetInput(IN_DIRECTIONAL_BLUR_IN, filterH);
+      return filterV.forget();
+    }
+    return nullptr;
+  }
+
+  static already_AddRefed<FilterNode>
+  Clear(DrawTarget* aDT)
+  {
+    RefPtr<FilterNode> filter = aDT->CreateFilter(FilterType::FLOOD);
+    if (filter) {
+      filter->SetAttribute(ATT_FLOOD_COLOR, Color(0, 0, 0, 0));
+      return filter.forget();
+    }
+    return nullptr;
+  }
+
+  static already_AddRefed<FilterNode>
+  ForSurface(DrawTarget* aDT, SourceSurface* aSurface,
+             const IntPoint& aSurfacePosition)
+  {
+    RefPtr<FilterNode> filter = aDT->CreateFilter(FilterType::TRANSFORM);
+    if (filter) {
+      filter->SetAttribute(ATT_TRANSFORM_MATRIX,
+        Matrix::Translation(aSurfacePosition.x, aSurfacePosition.y));
+      filter->SetInput(IN_TRANSFORM_IN, aSurface);
+      return filter.forget();
+    }
+    return nullptr;
+  }
+
+  static already_AddRefed<FilterNode>
+  ToAlpha(DrawTarget* aDT, FilterNode* aInput)
+  {
+    float zero = 0.0f;
+    RefPtr<FilterNode> transfer = aDT->CreateFilter(FilterType::DISCRETE_TRANSFER);
+    if (transfer) {
+      transfer->SetAttribute(ATT_DISCRETE_TRANSFER_DISABLE_R, false);
+      transfer->SetAttribute(ATT_DISCRETE_TRANSFER_TABLE_R, &zero, 1);
+      transfer->SetAttribute(ATT_DISCRETE_TRANSFER_DISABLE_G, false);
+      transfer->SetAttribute(ATT_DISCRETE_TRANSFER_TABLE_G, &zero, 1);
+      transfer->SetAttribute(ATT_DISCRETE_TRANSFER_DISABLE_B, false);
+      transfer->SetAttribute(ATT_DISCRETE_TRANSFER_TABLE_B, &zero, 1);
+      transfer->SetAttribute(ATT_DISCRETE_TRANSFER_DISABLE_A, true);
+      transfer->SetInput(IN_DISCRETE_TRANSFER_IN, aInput);
+      return transfer.forget();
+    }
+    return nullptr;
+  }
+
+} // namespace FilterWrappers
+
+// A class that wraps a FilterNode and handles conversion between different
+// color models. Create FilterCachedColorModels with your original filter and
+// the color model that this filter outputs in natively, and then call
+// ->ForColorModel(colorModel) in order to get a FilterNode which outputs to
+// the specified colorModel.
+// Internally, this is achieved by wrapping the original FilterNode with
+// conversion FilterNodes. These filter nodes are cached in such a way that no
+// repeated or back-and-forth conversions happen.
+class FilterCachedColorModels
+{
+public:
+  NS_INLINE_DECL_REFCOUNTING(FilterCachedColorModels)
+  // aFilter can be null. In that case, ForColorModel will return a non-null
+  // completely transparent filter for all color models.
+  FilterCachedColorModels(DrawTarget* aDT,
+                          FilterNode* aFilter,
+                          ColorModel aOriginalColorModel);
+
+  // Get a FilterNode for the specified color model, guaranteed to be non-null.
+  already_AddRefed<FilterNode> ForColorModel(ColorModel aColorModel);
+
+  AlphaModel OriginalAlphaModel() const { return mOriginalColorModel.mAlphaModel; }
+
+private:
+  // Create the required FilterNode that will be cached by ForColorModel.
+  already_AddRefed<FilterNode> WrapForColorModel(ColorModel aColorModel);
+
+  RefPtr<DrawTarget> mDT;
+  ColorModel mOriginalColorModel;
+
+  // This array is indexed by ColorModel::ToIndex.
+  RefPtr<FilterNode> mFilterForColorModel[4];
+
+  ~FilterCachedColorModels() {}
+};
+
+FilterCachedColorModels::FilterCachedColorModels(DrawTarget* aDT,
+                                                 FilterNode* aFilter,
+                                                 ColorModel aOriginalColorModel)
+ : mDT(aDT)
+ , mOriginalColorModel(aOriginalColorModel)
+{
+  if (aFilter) {
+    mFilterForColorModel[aOriginalColorModel.ToIndex()] = aFilter;
+  } else {
+    RefPtr<FilterNode> clear = FilterWrappers::Clear(aDT);
+    mFilterForColorModel[0] = clear;
+    mFilterForColorModel[1] = clear;
+    mFilterForColorModel[2] = clear;
+    mFilterForColorModel[3] = clear;
+  }
+}
+
+already_AddRefed<FilterNode>
+FilterCachedColorModels::ForColorModel(ColorModel aColorModel)
+{
+  if (aColorModel == mOriginalColorModel) {
+    // Make sure to not call WrapForColorModel if our original filter node was
+    // null, because then we'd get an infinite recursion.
+    RefPtr<FilterNode> filter = mFilterForColorModel[mOriginalColorModel.ToIndex()];
+    return filter.forget();
+  }
+
+  if (!mFilterForColorModel[aColorModel.ToIndex()]) {
+    mFilterForColorModel[aColorModel.ToIndex()] = WrapForColorModel(aColorModel);
+  }
+  RefPtr<FilterNode> filter(mFilterForColorModel[aColorModel.ToIndex()]);
+  return filter.forget();
+}
+
+already_AddRefed<FilterNode>
+FilterCachedColorModels::WrapForColorModel(ColorModel aColorModel)
+{
+  // Convert one aspect at a time and recurse.
+  // Conversions between premultiplied / unpremultiplied color channels for the
+  // same color space can happen directly.
+  // Conversions between different color spaces can only happen on
+  // unpremultiplied color channels.
+
+  if (aColorModel.mAlphaModel == AlphaModel::Premultiplied) {
+    RefPtr<FilterNode> unpre =
+      ForColorModel(ColorModel(aColorModel.mColorSpace, AlphaModel::Unpremultiplied));
+    return FilterWrappers::Premultiply(mDT, unpre);
+  }
+
+  MOZ_ASSERT(aColorModel.mAlphaModel == AlphaModel::Unpremultiplied);
+  if (aColorModel.mColorSpace == mOriginalColorModel.mColorSpace) {
+    RefPtr<FilterNode> premultiplied =
+      ForColorModel(ColorModel(aColorModel.mColorSpace, AlphaModel::Premultiplied));
+    return FilterWrappers::Unpremultiply(mDT, premultiplied);
+  }
+
+  RefPtr<FilterNode> unpremultipliedOriginal =
+    ForColorModel(ColorModel(mOriginalColorModel.mColorSpace, AlphaModel::Unpremultiplied));
+  if (aColorModel.mColorSpace == ColorSpace::LinearRGB) {
+    return FilterWrappers::SRGBToLinearRGB(mDT, unpremultipliedOriginal);
+  }
+  return FilterWrappers::LinearRGBToSRGB(mDT, unpremultipliedOriginal);
+}
+
+static const float identityMatrix[] =
+  { 1, 0, 0, 0, 0,
+    0, 1, 0, 0, 0,
+    0, 0, 1, 0, 0,
+    0, 0, 0, 1, 0 };
+
+// When aAmount == 0, the identity matrix is returned.
+// When aAmount == 1, aToMatrix is returned.
+// When aAmount > 1, an exaggerated version of aToMatrix is returned. This can
+// be useful in certain cases, such as producing a color matrix to oversaturate
+// an image.
+//
+// This function is a shortcut of a full matrix addition and a scalar multiply,
+// and it assumes that the following elements in aToMatrix are 0 and 1:
+//   x x x 0 0
+//   x x x 0 0
+//   x x x 0 0
+//   0 0 0 1 0
+static void
+InterpolateFromIdentityMatrix(const float aToMatrix[20], float aAmount,
+                              float aOutMatrix[20])
+{
+  PodCopy(aOutMatrix, identityMatrix, 20);
+
+  float oneMinusAmount = 1 - aAmount;
+
+  aOutMatrix[0] = aAmount * aToMatrix[0] + oneMinusAmount;
+  aOutMatrix[1] = aAmount * aToMatrix[1];
+  aOutMatrix[2] = aAmount * aToMatrix[2];
+
+  aOutMatrix[5] = aAmount * aToMatrix[5];
+  aOutMatrix[6] = aAmount * aToMatrix[6] + oneMinusAmount;
+  aOutMatrix[7] = aAmount * aToMatrix[7];
+
+  aOutMatrix[10] = aAmount * aToMatrix[10];
+  aOutMatrix[11] = aAmount * aToMatrix[11];
+  aOutMatrix[12] = aAmount * aToMatrix[12] + oneMinusAmount;
+}
+
+// Create a 4x5 color matrix for the different ways to specify color matrices
+// in SVG.
+static nsresult
+ComputeColorMatrix(uint32_t aColorMatrixType, const nsTArray<float>& aValues,
+                   float aOutMatrix[20])
+{
+  // Luminance coefficients.
+  static const float lumR = 0.2126f;
+  static const float lumG = 0.7152f;
+  static const float lumB = 0.0722f;
+
+  static const float oneMinusLumR = 1 - lumR;
+  static const float oneMinusLumG = 1 - lumG;
+  static const float oneMinusLumB = 1 - lumB;
+
+  static const float luminanceToAlphaMatrix[] =
+    { 0,    0,    0,    0, 0,
+      0,    0,    0,    0, 0,
+      0,    0,    0,    0, 0,
+      lumR, lumG, lumB, 0, 0 };
+
+  static const float saturateMatrix[] =
+    { lumR, lumG, lumB, 0, 0,
+      lumR, lumG, lumB, 0, 0,
+      lumR, lumG, lumB, 0, 0,
+      0,    0,    0,    1, 0 };
+
+  static const float sepiaMatrix[] =
+    { 0.393f, 0.769f, 0.189f, 0, 0,
+      0.349f, 0.686f, 0.168f, 0, 0,
+      0.272f, 0.534f, 0.131f, 0, 0,
+      0,      0,      0,      1, 0 };
+
+  // Hue rotate specific coefficients.
+  static const float hueRotateR = 0.143f;
+  static const float hueRotateG = 0.140f;
+  static const float hueRotateB = 0.283f;
+
+  switch (aColorMatrixType) {
+
+    case SVG_FECOLORMATRIX_TYPE_MATRIX:
+    {
+      if (aValues.Length() != 20) {
+        return NS_ERROR_FAILURE;
+      }
+
+      PodCopy(aOutMatrix, aValues.Elements(), 20);
+      break;
+    }
+
+    case SVG_FECOLORMATRIX_TYPE_SATURATE:
+    {
+      if (aValues.Length() != 1)
+        return NS_ERROR_FAILURE;
+
+      float s = aValues[0];
+
+      if (s < 0)
+        return NS_ERROR_FAILURE;
+
+      InterpolateFromIdentityMatrix(saturateMatrix, 1 - s, aOutMatrix);
+      break;
+    }
+
+    case SVG_FECOLORMATRIX_TYPE_HUE_ROTATE:
+    {
+      if (aValues.Length() != 1)
+        return NS_ERROR_FAILURE;
+
+      PodCopy(aOutMatrix, identityMatrix, 20);
+
+      float hueRotateValue = aValues[0];
+
+      float c = static_cast<float>(cos(hueRotateValue * M_PI / 180));
+      float s = static_cast<float>(sin(hueRotateValue * M_PI / 180));
+
+      aOutMatrix[0] = lumR + oneMinusLumR * c - lumR * s;
+      aOutMatrix[1] = lumG - lumG * c - lumG * s;
+      aOutMatrix[2] = lumB - lumB * c + oneMinusLumB * s;
+
+      aOutMatrix[5] = lumR - lumR * c + hueRotateR * s;
+      aOutMatrix[6] = lumG + oneMinusLumG * c + hueRotateG * s;
+      aOutMatrix[7] = lumB - lumB * c - hueRotateB * s;
+
+      aOutMatrix[10] = lumR - lumR * c - oneMinusLumR * s;
+      aOutMatrix[11] = lumG - lumG * c + lumG * s;
+      aOutMatrix[12] = lumB + oneMinusLumB * c + lumB * s;
+
+      break;
+    }
+
+    case SVG_FECOLORMATRIX_TYPE_LUMINANCE_TO_ALPHA:
+    {
+      PodCopy(aOutMatrix, luminanceToAlphaMatrix, 20);
+      break;
+    }
+
+    case SVG_FECOLORMATRIX_TYPE_SEPIA:
+    {
+      if (aValues.Length() != 1)
+        return NS_ERROR_FAILURE;
+
+      float amount = aValues[0];
+
+      if (amount < 0 || amount > 1)
+        return NS_ERROR_FAILURE;
+
+      InterpolateFromIdentityMatrix(sepiaMatrix, amount, aOutMatrix);
+      break;
+    }
+
+    default:
+      return NS_ERROR_FAILURE;
+
+  }
+
+  return NS_OK;
+}
+
+static void
+DisableAllTransfers(FilterNode* aTransferFilterNode)
+{
+  aTransferFilterNode->SetAttribute(ATT_TRANSFER_DISABLE_R, true);
+  aTransferFilterNode->SetAttribute(ATT_TRANSFER_DISABLE_G, true);
+  aTransferFilterNode->SetAttribute(ATT_TRANSFER_DISABLE_B, true);
+  aTransferFilterNode->SetAttribute(ATT_TRANSFER_DISABLE_A, true);
+}
+
+// Called for one channel at a time.
+// This function creates the required FilterNodes on demand and tries to
+// merge conversions of different channels into the same FilterNode if
+// possible.
+// There's a mismatch between the way SVG and the Moz2D API handle transfer
+// functions: In SVG, it's possible to specify a different transfer function
+// type for each color channel, but in Moz2D, a given transfer function type
+// applies to all color channels.
+//
+//  @param aFunctionAttributes The attributes of the transfer function for this
+//                             channel.
+//  @param aChannel The color channel that this function applies to, where
+//                  0 = red, 1 = green, 2 = blue, 3 = alpha
+//  @param aDT The DrawTarget that the FilterNodes should be created for.
+//  @param aTableTransfer Existing FilterNode holders (which may still be
+//                        null) that the resulting FilterNodes from this
+//                        function will be stored in.
+//           
+static void
+ConvertComponentTransferFunctionToFilter(const AttributeMap& aFunctionAttributes,
+                                         int32_t aChannel,
+                                         DrawTarget* aDT,
+                                         RefPtr<FilterNode>& aTableTransfer,
+                                         RefPtr<FilterNode>& aDiscreteTransfer,
+                                         RefPtr<FilterNode>& aLinearTransfer,
+                                         RefPtr<FilterNode>& aGammaTransfer)
+{
+  static const TransferAtts disableAtt[4] = {
+    ATT_TRANSFER_DISABLE_R,
+    ATT_TRANSFER_DISABLE_G,
+    ATT_TRANSFER_DISABLE_B,
+    ATT_TRANSFER_DISABLE_A
+  };
+
+  RefPtr<FilterNode> filter;
+
+  uint32_t type = aFunctionAttributes.GetUint(eComponentTransferFunctionType);
+
+  switch (type) {
+  case SVG_FECOMPONENTTRANSFER_TYPE_TABLE:
+  {
+    const nsTArray<float>& tableValues =
+      aFunctionAttributes.GetFloats(eComponentTransferFunctionTableValues);
+    if (tableValues.Length() < 2)
+      return;
+
+    if (!aTableTransfer) {
+      aTableTransfer = aDT->CreateFilter(FilterType::TABLE_TRANSFER);
+      if (!aTableTransfer) {
+        return;
+      }
+      DisableAllTransfers(aTableTransfer);
+    }
+    filter = aTableTransfer;
+    static const TableTransferAtts tableAtt[4] = {
+      ATT_TABLE_TRANSFER_TABLE_R,
+      ATT_TABLE_TRANSFER_TABLE_G,
+      ATT_TABLE_TRANSFER_TABLE_B,
+      ATT_TABLE_TRANSFER_TABLE_A
+    };
+    filter->SetAttribute(disableAtt[aChannel], false);
+    filter->SetAttribute(tableAtt[aChannel], &tableValues[0], tableValues.Length());
+    break;
+  }
+
+  case SVG_FECOMPONENTTRANSFER_TYPE_DISCRETE:
+  {
+    const nsTArray<float>& tableValues =
+      aFunctionAttributes.GetFloats(eComponentTransferFunctionTableValues);
+    if (tableValues.Length() < 1)
+      return;
+
+    if (!aDiscreteTransfer) {
+      aDiscreteTransfer = aDT->CreateFilter(FilterType::DISCRETE_TRANSFER);
+      if (!aDiscreteTransfer) {
+        return;
+      }
+      DisableAllTransfers(aDiscreteTransfer);
+    }
+    filter = aDiscreteTransfer;
+    static const DiscreteTransferAtts tableAtt[4] = {
+      ATT_DISCRETE_TRANSFER_TABLE_R,
+      ATT_DISCRETE_TRANSFER_TABLE_G,
+      ATT_DISCRETE_TRANSFER_TABLE_B,
+      ATT_DISCRETE_TRANSFER_TABLE_A
+    };
+    filter->SetAttribute(disableAtt[aChannel], false);
+    filter->SetAttribute(tableAtt[aChannel], &tableValues[0], tableValues.Length());
+
+    break;
+  }
+
+  case SVG_FECOMPONENTTRANSFER_TYPE_LINEAR:
+  {
+    static const LinearTransferAtts slopeAtt[4] = {
+      ATT_LINEAR_TRANSFER_SLOPE_R,
+      ATT_LINEAR_TRANSFER_SLOPE_G,
+      ATT_LINEAR_TRANSFER_SLOPE_B,
+      ATT_LINEAR_TRANSFER_SLOPE_A
+    };
+    static const LinearTransferAtts interceptAtt[4] = {
+      ATT_LINEAR_TRANSFER_INTERCEPT_R,
+      ATT_LINEAR_TRANSFER_INTERCEPT_G,
+      ATT_LINEAR_TRANSFER_INTERCEPT_B,
+      ATT_LINEAR_TRANSFER_INTERCEPT_A
+    };
+    if (!aLinearTransfer) {
+      aLinearTransfer = aDT->CreateFilter(FilterType::LINEAR_TRANSFER);
+      if (!aLinearTransfer) {
+        return;
+      }
+      DisableAllTransfers(aLinearTransfer);
+    }
+    filter = aLinearTransfer;
+    filter->SetAttribute(disableAtt[aChannel], false);
+    float slope = aFunctionAttributes.GetFloat(eComponentTransferFunctionSlope);
+    float intercept = aFunctionAttributes.GetFloat(eComponentTransferFunctionIntercept);
+    filter->SetAttribute(slopeAtt[aChannel], slope);
+    filter->SetAttribute(interceptAtt[aChannel], intercept);
+    break;
+  }
+
+  case SVG_FECOMPONENTTRANSFER_TYPE_GAMMA:
+  {
+    static const GammaTransferAtts amplitudeAtt[4] = {
+      ATT_GAMMA_TRANSFER_AMPLITUDE_R,
+      ATT_GAMMA_TRANSFER_AMPLITUDE_G,
+      ATT_GAMMA_TRANSFER_AMPLITUDE_B,
+      ATT_GAMMA_TRANSFER_AMPLITUDE_A
+    };
+    static const GammaTransferAtts exponentAtt[4] = {
+      ATT_GAMMA_TRANSFER_EXPONENT_R,
+      ATT_GAMMA_TRANSFER_EXPONENT_G,
+      ATT_GAMMA_TRANSFER_EXPONENT_B,
+      ATT_GAMMA_TRANSFER_EXPONENT_A
+    };
+    static const GammaTransferAtts offsetAtt[4] = {
+      ATT_GAMMA_TRANSFER_OFFSET_R,
+      ATT_GAMMA_TRANSFER_OFFSET_G,
+      ATT_GAMMA_TRANSFER_OFFSET_B,
+      ATT_GAMMA_TRANSFER_OFFSET_A
+    };
+    if (!aGammaTransfer) {
+      aGammaTransfer = aDT->CreateFilter(FilterType::GAMMA_TRANSFER);
+      if (!aGammaTransfer) {
+        return;
+      }
+      DisableAllTransfers(aGammaTransfer);
+    }
+    filter = aGammaTransfer;
+    filter->SetAttribute(disableAtt[aChannel], false);
+    float amplitude = aFunctionAttributes.GetFloat(eComponentTransferFunctionAmplitude);
+    float exponent = aFunctionAttributes.GetFloat(eComponentTransferFunctionExponent);
+    float offset = aFunctionAttributes.GetFloat(eComponentTransferFunctionOffset);
+    filter->SetAttribute(amplitudeAtt[aChannel], amplitude);
+    filter->SetAttribute(exponentAtt[aChannel], exponent);
+    filter->SetAttribute(offsetAtt[aChannel], offset);
+    break;
+  }
+
+  case SVG_FECOMPONENTTRANSFER_TYPE_IDENTITY:
+  default:
+    break;
+  }
+}
+
+const int32_t kMorphologyMaxRadius = 100000;
+
+// Handle the different primitive description types and create the necessary
+// FilterNode(s) for each.
+// Returns nullptr for invalid filter primitives. This should be interpreted as
+// transparent black by the caller.
+// aSourceRegions contains the filter primitive subregions of the source
+// primitives; only needed for eTile primitives.
+// aInputImages carries additional surfaces that are used by eImage primitives.
+static already_AddRefed<FilterNode>
+FilterNodeFromPrimitiveDescription(const FilterPrimitiveDescription& aDescription,
+                                   DrawTarget* aDT,
+                                   nsTArray<RefPtr<FilterNode> >& aSources,
+                                   nsTArray<IntRect>& aSourceRegions,
+                                   nsTArray<RefPtr<SourceSurface>>& aInputImages)
+{
+  const AttributeMap& atts = aDescription.Attributes();
+  switch (aDescription.Type()) {
+
+    case PrimitiveType::Empty:
+      return nullptr;
+
+    case PrimitiveType::Blend:
+    {
+      uint32_t mode = atts.GetUint(eBlendBlendmode);
+      RefPtr<FilterNode> filter;
+      if (mode == SVG_FEBLEND_MODE_UNKNOWN) {
+        return nullptr;
+      }
+      if (mode == SVG_FEBLEND_MODE_NORMAL) {
+        filter = aDT->CreateFilter(FilterType::COMPOSITE);
+        if (!filter) {
+          return nullptr;
+        }
+        filter->SetInput(IN_COMPOSITE_IN_START, aSources[1]);
+        filter->SetInput(IN_COMPOSITE_IN_START + 1, aSources[0]);
+      } else {
+        filter = aDT->CreateFilter(FilterType::BLEND);
+        if (!filter) {
+          return nullptr;
+        }
+        static const uint8_t blendModes[SVG_FEBLEND_MODE_LUMINOSITY + 1] = {
+          0,
+          0,
+          BLEND_MODE_MULTIPLY,
+          BLEND_MODE_SCREEN,
+          BLEND_MODE_DARKEN,
+          BLEND_MODE_LIGHTEN,
+          BLEND_MODE_OVERLAY,
+          BLEND_MODE_COLOR_DODGE,
+          BLEND_MODE_COLOR_BURN,
+          BLEND_MODE_HARD_LIGHT,
+          BLEND_MODE_SOFT_LIGHT,
+          BLEND_MODE_DIFFERENCE,
+          BLEND_MODE_EXCLUSION,
+          BLEND_MODE_HUE,
+          BLEND_MODE_SATURATION,
+          BLEND_MODE_COLOR,
+          BLEND_MODE_LUMINOSITY
+        };
+        filter->SetAttribute(ATT_BLEND_BLENDMODE, (uint32_t)blendModes[mode]);
+        // The correct input order for both software and D2D filters is flipped
+        // from our source order, so flip here.
+        filter->SetInput(IN_BLEND_IN, aSources[1]);
+        filter->SetInput(IN_BLEND_IN2, aSources[0]);
+      }
+      return filter.forget();
+    }
+
+    case PrimitiveType::ColorMatrix:
+    {
+      float colorMatrix[20];
+      uint32_t type = atts.GetUint(eColorMatrixType);
+      const nsTArray<float>& values = atts.GetFloats(eColorMatrixValues);
+      if (NS_FAILED(ComputeColorMatrix(type, values, colorMatrix)) ||
+          PodEqual(colorMatrix, identityMatrix)) {
+        RefPtr<FilterNode> filter(aSources[0]);
+        return filter.forget();
+      }
+      Matrix5x4 matrix(colorMatrix[0], colorMatrix[5], colorMatrix[10],  colorMatrix[15],
+                       colorMatrix[1], colorMatrix[6], colorMatrix[11],  colorMatrix[16],
+                       colorMatrix[2], colorMatrix[7], colorMatrix[12],  colorMatrix[17],
+                       colorMatrix[3], colorMatrix[8], colorMatrix[13],  colorMatrix[18],
+                       colorMatrix[4], colorMatrix[9], colorMatrix[14],  colorMatrix[19]);
+      RefPtr<FilterNode> filter = aDT->CreateFilter(FilterType::COLOR_MATRIX);
+      if (!filter) {
+        return nullptr;
+      }
+      filter->SetAttribute(ATT_COLOR_MATRIX_MATRIX, matrix);
+      filter->SetAttribute(ATT_COLOR_MATRIX_ALPHA_MODE, (uint32_t)ALPHA_MODE_STRAIGHT);
+      filter->SetInput(IN_COLOR_MATRIX_IN, aSources[0]);
+      return filter.forget();
+    }
+
+    case PrimitiveType::Morphology:
+    {
+      Size radii = atts.GetSize(eMorphologyRadii);
+      int32_t rx = radii.width;
+      int32_t ry = radii.height;
+      if (rx < 0 || ry < 0) {
+        // XXX SVGContentUtils::ReportToConsole()
+        return nullptr;
+      }
+      if (rx == 0 && ry == 0) {
+        return nullptr;
+      }
+
+      // Clamp radii to prevent completely insane values:
+      rx = std::min(rx, kMorphologyMaxRadius);
+      ry = std::min(ry, kMorphologyMaxRadius);
+
+      MorphologyOperator op = atts.GetUint(eMorphologyOperator) == SVG_OPERATOR_ERODE ?
+        MORPHOLOGY_OPERATOR_ERODE : MORPHOLOGY_OPERATOR_DILATE;
+
+      RefPtr<FilterNode> filter = aDT->CreateFilter(FilterType::MORPHOLOGY);
+      if (!filter) {
+        return nullptr;
+      }
+      filter->SetAttribute(ATT_MORPHOLOGY_RADII, IntSize(rx, ry));
+      filter->SetAttribute(ATT_MORPHOLOGY_OPERATOR, (uint32_t)op);
+      filter->SetInput(IN_MORPHOLOGY_IN, aSources[0]);
+      return filter.forget();
+    }
+
+    case PrimitiveType::Flood:
+    {
+      Color color = atts.GetColor(eFloodColor);
+      RefPtr<FilterNode> filter = aDT->CreateFilter(FilterType::FLOOD);
+      if (!filter) {
+        return nullptr;
+      }
+      filter->SetAttribute(ATT_FLOOD_COLOR, color);
+      return filter.forget();
+    }
+
+    case PrimitiveType::Tile:
+    {
+      RefPtr<FilterNode> filter = aDT->CreateFilter(FilterType::TILE);
+      if (!filter) {
+        return nullptr;
+      }
+      filter->SetAttribute(ATT_TILE_SOURCE_RECT, aSourceRegions[0]);
+      filter->SetInput(IN_TILE_IN, aSources[0]);
+      return filter.forget();
+    }
+
+    case PrimitiveType::ComponentTransfer:
+    {
+      RefPtr<FilterNode> filters[4]; // one for each FILTER_*_TRANSFER type
+      static const AttributeName componentFunctionNames[4] = {
+        eComponentTransferFunctionR,
+        eComponentTransferFunctionG,
+        eComponentTransferFunctionB,
+        eComponentTransferFunctionA
+      };
+      for (int32_t i = 0; i < 4; i++) {
+        AttributeMap functionAttributes =
+          atts.GetAttributeMap(componentFunctionNames[i]);
+        ConvertComponentTransferFunctionToFilter(functionAttributes, i, aDT,
+          filters[0], filters[1], filters[2], filters[3]);
+      }
+
+      // Connect all used filters nodes.
+      RefPtr<FilterNode> lastFilter = aSources[0];
+      for (int32_t i = 0; i < 4; i++) {
+        if (filters[i]) {
+          filters[i]->SetInput(0, lastFilter);
+          lastFilter = filters[i];
+        }
+      }
+
+      return lastFilter.forget();
+    }
+
+    case PrimitiveType::ConvolveMatrix:
+    {
+      RefPtr<FilterNode> filter = aDT->CreateFilter(FilterType::CONVOLVE_MATRIX);
+      if (!filter) {
+        return nullptr;
+      }
+      filter->SetAttribute(ATT_CONVOLVE_MATRIX_KERNEL_SIZE, atts.GetIntSize(eConvolveMatrixKernelSize));
+      const nsTArray<float>& matrix = atts.GetFloats(eConvolveMatrixKernelMatrix);
+      filter->SetAttribute(ATT_CONVOLVE_MATRIX_KERNEL_MATRIX,
+                           matrix.Elements(), matrix.Length());
+      filter->SetAttribute(ATT_CONVOLVE_MATRIX_DIVISOR,
+                           atts.GetFloat(eConvolveMatrixDivisor));
+      filter->SetAttribute(ATT_CONVOLVE_MATRIX_BIAS,
+                           atts.GetFloat(eConvolveMatrixBias));
+      filter->SetAttribute(ATT_CONVOLVE_MATRIX_TARGET,
+                           atts.GetIntPoint(eConvolveMatrixTarget));
+      filter->SetAttribute(ATT_CONVOLVE_MATRIX_SOURCE_RECT,
+                           aSourceRegions[0]);
+      uint32_t edgeMode = atts.GetUint(eConvolveMatrixEdgeMode);
+      static const uint8_t edgeModes[SVG_EDGEMODE_NONE+1] = {
+        EDGE_MODE_NONE,      // SVG_EDGEMODE_UNKNOWN
+        EDGE_MODE_DUPLICATE, // SVG_EDGEMODE_DUPLICATE
+        EDGE_MODE_WRAP,      // SVG_EDGEMODE_WRAP
+        EDGE_MODE_NONE       // SVG_EDGEMODE_NONE
+      };
+      filter->SetAttribute(ATT_CONVOLVE_MATRIX_EDGE_MODE, (uint32_t)edgeModes[edgeMode]);
+      filter->SetAttribute(ATT_CONVOLVE_MATRIX_KERNEL_UNIT_LENGTH,
+                           atts.GetSize(eConvolveMatrixKernelUnitLength));
+      filter->SetAttribute(ATT_CONVOLVE_MATRIX_PRESERVE_ALPHA,
+                           atts.GetBool(eConvolveMatrixPreserveAlpha));
+      filter->SetInput(IN_CONVOLVE_MATRIX_IN, aSources[0]);
+      return filter.forget();
+    }
+
+    case PrimitiveType::Offset:
+    {
+      return FilterWrappers::Offset(aDT, aSources[0],
+                                    atts.GetIntPoint(eOffsetOffset));
+    }
+
+    case PrimitiveType::DisplacementMap:
+    {
+      RefPtr<FilterNode> filter = aDT->CreateFilter(FilterType::DISPLACEMENT_MAP);
+      if (!filter) {
+        return nullptr;
+      }
+      filter->SetAttribute(ATT_DISPLACEMENT_MAP_SCALE,
+                           atts.GetFloat(eDisplacementMapScale));
+      static const uint8_t channel[SVG_CHANNEL_A+1] = {
+        COLOR_CHANNEL_R, // SVG_CHANNEL_UNKNOWN
+        COLOR_CHANNEL_R, // SVG_CHANNEL_R
+        COLOR_CHANNEL_G, // SVG_CHANNEL_G
+        COLOR_CHANNEL_B, // SVG_CHANNEL_B
+        COLOR_CHANNEL_A  // SVG_CHANNEL_A
+      };
+      filter->SetAttribute(ATT_DISPLACEMENT_MAP_X_CHANNEL,
+                           (uint32_t)channel[atts.GetUint(eDisplacementMapXChannel)]);
+      filter->SetAttribute(ATT_DISPLACEMENT_MAP_Y_CHANNEL,
+                           (uint32_t)channel[atts.GetUint(eDisplacementMapYChannel)]);
+      filter->SetInput(IN_DISPLACEMENT_MAP_IN, aSources[0]);
+      filter->SetInput(IN_DISPLACEMENT_MAP_IN2, aSources[1]);
+      return filter.forget();
+    }
+
+    case PrimitiveType::Turbulence:
+    {
+      RefPtr<FilterNode> filter = aDT->CreateFilter(FilterType::TURBULENCE);
+      if (!filter) {
+        return nullptr;
+      }
+      filter->SetAttribute(ATT_TURBULENCE_BASE_FREQUENCY,
+                           atts.GetSize(eTurbulenceBaseFrequency));
+      filter->SetAttribute(ATT_TURBULENCE_NUM_OCTAVES,
+                           atts.GetUint(eTurbulenceNumOctaves));
+      filter->SetAttribute(ATT_TURBULENCE_STITCHABLE,
+                           atts.GetBool(eTurbulenceStitchable));
+      filter->SetAttribute(ATT_TURBULENCE_SEED,
+                           (uint32_t)atts.GetFloat(eTurbulenceSeed));
+      static const uint8_t type[SVG_TURBULENCE_TYPE_TURBULENCE+1] = {
+        TURBULENCE_TYPE_FRACTAL_NOISE, // SVG_TURBULENCE_TYPE_UNKNOWN
+        TURBULENCE_TYPE_FRACTAL_NOISE, // SVG_TURBULENCE_TYPE_FRACTALNOISE
+        TURBULENCE_TYPE_TURBULENCE     // SVG_TURBULENCE_TYPE_TURBULENCE
+      };
+      filter->SetAttribute(ATT_TURBULENCE_TYPE,
+                           (uint32_t)type[atts.GetUint(eTurbulenceType)]);
+      filter->SetAttribute(ATT_TURBULENCE_RECT,
+                           aDescription.PrimitiveSubregion() - atts.GetIntPoint(eTurbulenceOffset));
+      return FilterWrappers::Offset(aDT, filter, atts.GetIntPoint(eTurbulenceOffset));
+    }
+
+    case PrimitiveType::Composite:
+    {
+      RefPtr<FilterNode> filter;
+      uint32_t op = atts.GetUint(eCompositeOperator);
+      if (op == SVG_FECOMPOSITE_OPERATOR_ARITHMETIC) {
+        const nsTArray<float>& coefficients = atts.GetFloats(eCompositeCoefficients);
+        static const float allZero[4] = { 0, 0, 0, 0 };
+        filter = aDT->CreateFilter(FilterType::ARITHMETIC_COMBINE);
+        // All-zero coefficients sometimes occur in junk filters.
+        if (!filter ||
+            (coefficients.Length() == ArrayLength(allZero) &&
+             PodEqual(coefficients.Elements(), allZero, ArrayLength(allZero)))) {
+          return nullptr;
+        }
+        filter->SetAttribute(ATT_ARITHMETIC_COMBINE_COEFFICIENTS,
+                             coefficients.Elements(), coefficients.Length());
+        filter->SetInput(IN_ARITHMETIC_COMBINE_IN, aSources[0]);
+        filter->SetInput(IN_ARITHMETIC_COMBINE_IN2, aSources[1]);
+      } else {
+        filter = aDT->CreateFilter(FilterType::COMPOSITE);
+        if (!filter) {
+          return nullptr;
+        }
+        static const uint8_t operators[SVG_FECOMPOSITE_OPERATOR_ARITHMETIC] = {
+          COMPOSITE_OPERATOR_OVER, // SVG_FECOMPOSITE_OPERATOR_UNKNOWN
+          COMPOSITE_OPERATOR_OVER, // SVG_FECOMPOSITE_OPERATOR_OVER
+          COMPOSITE_OPERATOR_IN,   // SVG_FECOMPOSITE_OPERATOR_IN
+          COMPOSITE_OPERATOR_OUT,  // SVG_FECOMPOSITE_OPERATOR_OUT
+          COMPOSITE_OPERATOR_ATOP, // SVG_FECOMPOSITE_OPERATOR_ATOP
+          COMPOSITE_OPERATOR_XOR   // SVG_FECOMPOSITE_OPERATOR_XOR
+        };
+        filter->SetAttribute(ATT_COMPOSITE_OPERATOR, (uint32_t)operators[op]);
+        filter->SetInput(IN_COMPOSITE_IN_START, aSources[1]);
+        filter->SetInput(IN_COMPOSITE_IN_START + 1, aSources[0]);
+      }
+      return filter.forget();
+    }
+
+    case PrimitiveType::Merge:
+    {
+      if (aSources.Length() == 0) {
+        return nullptr;
+      }
+      if (aSources.Length() == 1) {
+        RefPtr<FilterNode> filter(aSources[0]);
+        return filter.forget();
+      }
+      RefPtr<FilterNode> filter = aDT->CreateFilter(FilterType::COMPOSITE);
+      if (!filter) {
+        return nullptr;
+      }
+      filter->SetAttribute(ATT_COMPOSITE_OPERATOR, (uint32_t)COMPOSITE_OPERATOR_OVER);
+      for (size_t i = 0; i < aSources.Length(); i++) {
+        filter->SetInput(IN_COMPOSITE_IN_START + i, aSources[i]);
+      }
+      return filter.forget();
+    }
+
+    case PrimitiveType::GaussianBlur:
+    {
+      return FilterWrappers::GaussianBlur(aDT, aSources[0],
+                                          atts.GetSize(eGaussianBlurStdDeviation));
+    }
+
+    case PrimitiveType::DropShadow:
+    {
+      RefPtr<FilterNode> alpha = FilterWrappers::ToAlpha(aDT, aSources[0]);
+      RefPtr<FilterNode> blur = FilterWrappers::GaussianBlur(aDT, alpha,
+                                  atts.GetSize(eDropShadowStdDeviation));
+      RefPtr<FilterNode> offsetBlur = FilterWrappers::Offset(aDT, blur,
+                                        atts.GetIntPoint(eDropShadowOffset));
+      RefPtr<FilterNode> flood = aDT->CreateFilter(FilterType::FLOOD);
+      if (!flood) {
+        return nullptr;
+      }
+      Color color = atts.GetColor(eDropShadowColor);
+      if (aDescription.InputColorSpace(0) == ColorSpace::LinearRGB) {
+        color = Color(gsRGBToLinearRGBMap[uint8_t(color.r * 255)],
+                      gsRGBToLinearRGBMap[uint8_t(color.g * 255)],
+                      gsRGBToLinearRGBMap[uint8_t(color.b * 255)],
+                      color.a);
+      }
+      flood->SetAttribute(ATT_FLOOD_COLOR, color);
+
+      RefPtr<FilterNode> composite = aDT->CreateFilter(FilterType::COMPOSITE);
+      if (!composite) {
+        return nullptr;
+      }
+      composite->SetAttribute(ATT_COMPOSITE_OPERATOR, (uint32_t)COMPOSITE_OPERATOR_IN);
+      composite->SetInput(IN_COMPOSITE_IN_START, offsetBlur);
+      composite->SetInput(IN_COMPOSITE_IN_START + 1, flood);
+
+      RefPtr<FilterNode> filter = aDT->CreateFilter(FilterType::COMPOSITE);
+      if (!filter) {
+        return nullptr;
+      }
+      filter->SetAttribute(ATT_COMPOSITE_OPERATOR, (uint32_t)COMPOSITE_OPERATOR_OVER);
+      filter->SetInput(IN_COMPOSITE_IN_START, composite);
+      filter->SetInput(IN_COMPOSITE_IN_START + 1, aSources[0]);
+      return filter.forget();
+    }
+
+    case PrimitiveType::DiffuseLighting:
+    case PrimitiveType::SpecularLighting:
+    {
+      bool isSpecular =
+        aDescription.Type() == PrimitiveType::SpecularLighting;
+
+      AttributeMap lightAttributes = atts.GetAttributeMap(eLightingLight);
+
+      if (lightAttributes.GetUint(eLightType) == eLightTypeNone) {
+        return nullptr;
+      }
+
+      enum { POINT = 0, SPOT, DISTANT } lightType = POINT;
+
+      switch (lightAttributes.GetUint(eLightType)) {
+        case eLightTypePoint:   lightType = POINT;   break;
+        case eLightTypeSpot:    lightType = SPOT;    break;
+        case eLightTypeDistant: lightType = DISTANT; break;
+      }
+
+      static const FilterType filterType[2][DISTANT+1] = {
+        { FilterType::POINT_DIFFUSE, FilterType::SPOT_DIFFUSE, FilterType::DISTANT_DIFFUSE },
+        { FilterType::POINT_SPECULAR, FilterType::SPOT_SPECULAR, FilterType::DISTANT_SPECULAR }
+      };
+      RefPtr<FilterNode> filter =
+        aDT->CreateFilter(filterType[isSpecular][lightType]);
+      if (!filter) {
+        return nullptr;
+      }
+
+      filter->SetAttribute(ATT_LIGHTING_COLOR,
+                           atts.GetColor(eLightingColor));
+      filter->SetAttribute(ATT_LIGHTING_SURFACE_SCALE,
+                           atts.GetFloat(eLightingSurfaceScale));
+      filter->SetAttribute(ATT_LIGHTING_KERNEL_UNIT_LENGTH,
+                           atts.GetSize(eLightingKernelUnitLength));
+
+      if (isSpecular) {
+        filter->SetAttribute(ATT_SPECULAR_LIGHTING_SPECULAR_CONSTANT,
+                             atts.GetFloat(eSpecularLightingSpecularConstant));
+        filter->SetAttribute(ATT_SPECULAR_LIGHTING_SPECULAR_EXPONENT,
+                             atts.GetFloat(eSpecularLightingSpecularExponent));
+      } else {
+        filter->SetAttribute(ATT_DIFFUSE_LIGHTING_DIFFUSE_CONSTANT,
+                             atts.GetFloat(eDiffuseLightingDiffuseConstant));
+      }
+
+      switch (lightType) {
+        case POINT:
+          filter->SetAttribute(ATT_POINT_LIGHT_POSITION,
+                               lightAttributes.GetPoint3D(ePointLightPosition));
+          break;
+        case SPOT:
+          filter->SetAttribute(ATT_SPOT_LIGHT_POSITION,
+                               lightAttributes.GetPoint3D(eSpotLightPosition));
+          filter->SetAttribute(ATT_SPOT_LIGHT_POINTS_AT,
+                               lightAttributes.GetPoint3D(eSpotLightPointsAt));
+          filter->SetAttribute(ATT_SPOT_LIGHT_FOCUS,
+                               lightAttributes.GetFloat(eSpotLightFocus));
+          filter->SetAttribute(ATT_SPOT_LIGHT_LIMITING_CONE_ANGLE,
+                               lightAttributes.GetFloat(eSpotLightLimitingConeAngle));
+          break;
+        case DISTANT:
+          filter->SetAttribute(ATT_DISTANT_LIGHT_AZIMUTH,
+                               lightAttributes.GetFloat(eDistantLightAzimuth));
+          filter->SetAttribute(ATT_DISTANT_LIGHT_ELEVATION,
+                               lightAttributes.GetFloat(eDistantLightElevation));
+          break;
+      }
+
+      filter->SetInput(IN_LIGHTING_IN, aSources[0]);
+
+      return filter.forget();
+    }
+
+    case PrimitiveType::Image:
+    {
+      Matrix TM = atts.GetMatrix(eImageTransform);
+      if (!TM.Determinant()) {
+        return nullptr;
+      }
+
+      // Pull the image from the additional image list using the index that's
+      // stored in the primitive description.
+      RefPtr<SourceSurface> inputImage =
+        aInputImages[atts.GetUint(eImageInputIndex)];
+
+      RefPtr<FilterNode> transform = aDT->CreateFilter(FilterType::TRANSFORM);
+      if (!transform) {
+        return nullptr;
+      }
+      transform->SetInput(IN_TRANSFORM_IN, inputImage);
+      transform->SetAttribute(ATT_TRANSFORM_MATRIX, TM);
+      transform->SetAttribute(ATT_TRANSFORM_FILTER, atts.GetUint(eImageFilter));
+      return transform.forget();
+    }
+
+    case PrimitiveType::ToAlpha:
+    {
+      return FilterWrappers::ToAlpha(aDT, aSources[0]);
+    }
+
+    default:
+      return nullptr;
+  }
+}
+
+template<typename T>
+static const T&
+ElementForIndex(int32_t aIndex,
+                const nsTArray<T>& aPrimitiveElements,
+                const T& aSourceGraphicElement,
+                const T& aFillPaintElement,
+                const T& aStrokePaintElement)
+{
+  switch (aIndex) {
+    case FilterPrimitiveDescription::kPrimitiveIndexSourceGraphic:
+    case FilterPrimitiveDescription::kPrimitiveIndexSourceAlpha:
+      return aSourceGraphicElement;
+    case FilterPrimitiveDescription::kPrimitiveIndexFillPaint:
+      return aFillPaintElement;
+    case FilterPrimitiveDescription::kPrimitiveIndexStrokePaint:
+      return aStrokePaintElement;
+    default:
+      MOZ_ASSERT(aIndex >= 0, "bad index");
+      return aPrimitiveElements[aIndex];
+  }
+}
+
+static AlphaModel
+InputAlphaModelForPrimitive(const FilterPrimitiveDescription& aDescr,
+                            int32_t aInputIndex,
+                            AlphaModel aOriginalAlphaModel)
+{
+  switch (aDescr.Type()) {
+    case PrimitiveType::Tile:
+    case PrimitiveType::Offset:
+    case PrimitiveType::ToAlpha:
+      return aOriginalAlphaModel;
+
+    case PrimitiveType::ColorMatrix:
+    case PrimitiveType::ComponentTransfer:
+      return AlphaModel::Unpremultiplied;
+
+    case PrimitiveType::DisplacementMap:
+      return aInputIndex == 0 ?
+        AlphaModel::Premultiplied : AlphaModel::Unpremultiplied;
+
+    case PrimitiveType::ConvolveMatrix:
+      return aDescr.Attributes().GetBool(eConvolveMatrixPreserveAlpha) ?
+        AlphaModel::Unpremultiplied : AlphaModel::Premultiplied;
+
+    default:
+      return AlphaModel::Premultiplied;
+  }
+}
+
+static AlphaModel
+OutputAlphaModelForPrimitive(const FilterPrimitiveDescription& aDescr,
+                             const nsTArray<AlphaModel>& aInputAlphaModels)
+{
+  if (aInputAlphaModels.Length()) {
+    // For filters with inputs, the output is premultiplied if and only if the
+    // first input is premultiplied.
+    return InputAlphaModelForPrimitive(aDescr, 0, aInputAlphaModels[0]);
+  }
+
+  // All filters without inputs produce premultiplied alpha.
+  return AlphaModel::Premultiplied;
+}
+
+// Returns the output FilterNode, in premultiplied sRGB space.
+static already_AddRefed<FilterNode>
+FilterNodeGraphFromDescription(DrawTarget* aDT,
+                               const FilterDescription& aFilter,
+                               const Rect& aResultNeededRect,
+                               SourceSurface* aSourceGraphic,
+                               const IntRect& aSourceGraphicRect,
+                               SourceSurface* aFillPaint,
+                               const IntRect& aFillPaintRect,
+                               SourceSurface* aStrokePaint,
+                               const IntRect& aStrokePaintRect,
+                               nsTArray<RefPtr<SourceSurface>>& aAdditionalImages)
+{
+  const nsTArray<FilterPrimitiveDescription>& primitives = aFilter.mPrimitives;
+  MOZ_RELEASE_ASSERT(!primitives.IsEmpty());
+
+  RefPtr<FilterCachedColorModels> sourceFilters[4];
+  nsTArray<RefPtr<FilterCachedColorModels> > primitiveFilters;
+
+  for (size_t i = 0; i < primitives.Length(); ++i) {
+    const FilterPrimitiveDescription& descr = primitives[i];
+
+    nsTArray<RefPtr<FilterNode> > inputFilterNodes;
+    nsTArray<IntRect> inputSourceRects;
+    nsTArray<AlphaModel> inputAlphaModels;
+
+    for (size_t j = 0; j < descr.NumberOfInputs(); j++) {
+
+      int32_t inputIndex = descr.InputPrimitiveIndex(j);
+      if (inputIndex < 0) {
+        inputSourceRects.AppendElement(descr.FilterSpaceBounds());
+      } else {
+        inputSourceRects.AppendElement(primitives[inputIndex].PrimitiveSubregion());
+      }
+
+      RefPtr<FilterCachedColorModels> inputFilter;
+      if (inputIndex >= 0) {
+        MOZ_ASSERT(inputIndex < (int64_t)primitiveFilters.Length(), "out-of-bounds input index!");
+        inputFilter = primitiveFilters[inputIndex];
+        MOZ_ASSERT(inputFilter, "Referred to input filter that comes after the current one?");
+      } else {
+        int32_t sourceIndex = -inputIndex - 1;
+        MOZ_ASSERT(sourceIndex >= 0, "invalid source index");
+        MOZ_ASSERT(sourceIndex < 4, "invalid source index");
+        inputFilter = sourceFilters[sourceIndex];
+        if (!inputFilter) {
+          RefPtr<FilterNode> sourceFilterNode;
+
+          nsTArray<SourceSurface*> primitiveSurfaces;
+          nsTArray<IntRect> primitiveSurfaceRects;
+          RefPtr<SourceSurface> surf =
+            ElementForIndex(inputIndex, primitiveSurfaces,
+                            aSourceGraphic, aFillPaint, aStrokePaint);
+          IntRect surfaceRect =
+            ElementForIndex(inputIndex, primitiveSurfaceRects,
+                            aSourceGraphicRect, aFillPaintRect, aStrokePaintRect);
+          if (surf) {
+            IntPoint offset = surfaceRect.TopLeft();
+            sourceFilterNode = FilterWrappers::ForSurface(aDT, surf, offset);
+
+            // Clip the original SourceGraphic to the first filter region if the
+            // surface isn't already sized appropriately.
+            if ((inputIndex == FilterPrimitiveDescription::kPrimitiveIndexSourceGraphic ||
+                 inputIndex == FilterPrimitiveDescription::kPrimitiveIndexSourceAlpha) &&
+                !descr.FilterSpaceBounds().Contains(aSourceGraphicRect)) {
+              sourceFilterNode =
+                FilterWrappers::Crop(aDT, sourceFilterNode, descr.FilterSpaceBounds());
+            }
+
+            if (inputIndex == FilterPrimitiveDescription::kPrimitiveIndexSourceAlpha) {
+              sourceFilterNode = FilterWrappers::ToAlpha(aDT, sourceFilterNode);
+            }
+          }
+
+          inputFilter = new FilterCachedColorModels(aDT, sourceFilterNode,
+                                                    ColorModel::PremulSRGB());
+          sourceFilters[sourceIndex] = inputFilter;
+        }
+      }
+      MOZ_ASSERT(inputFilter);
+
+      AlphaModel inputAlphaModel =
+        InputAlphaModelForPrimitive(descr, j, inputFilter->OriginalAlphaModel());
+      inputAlphaModels.AppendElement(inputAlphaModel);
+      ColorModel inputColorModel(descr.InputColorSpace(j), inputAlphaModel);
+      inputFilterNodes.AppendElement(inputFilter->ForColorModel(inputColorModel));
+    }
+
+    RefPtr<FilterNode> primitiveFilterNode =
+      FilterNodeFromPrimitiveDescription(descr, aDT, inputFilterNodes,
+                                         inputSourceRects, aAdditionalImages);
+
+    if (primitiveFilterNode) {
+      primitiveFilterNode =
+        FilterWrappers::Crop(aDT, primitiveFilterNode, descr.PrimitiveSubregion());
+    }
+
+    ColorModel outputColorModel(descr.OutputColorSpace(),
+      OutputAlphaModelForPrimitive(descr, inputAlphaModels));
+    RefPtr<FilterCachedColorModels> primitiveFilter =
+      new FilterCachedColorModels(aDT, primitiveFilterNode, outputColorModel);
+
+    primitiveFilters.AppendElement(primitiveFilter);
+  }
+
+  MOZ_RELEASE_ASSERT(!primitiveFilters.IsEmpty());
+  return primitiveFilters.LastElement()->ForColorModel(ColorModel::PremulSRGB());
+}
+
+// FilterSupport
+
+void
+FilterSupport::RenderFilterDescription(DrawTarget* aDT,
+                                       const FilterDescription& aFilter,
+                                       const Rect& aRenderRect,
+                                       SourceSurface* aSourceGraphic,
+                                       const IntRect& aSourceGraphicRect,
+                                       SourceSurface* aFillPaint,
+                                       const IntRect& aFillPaintRect,
+                                       SourceSurface* aStrokePaint,
+                                       const IntRect& aStrokePaintRect,
+                                       nsTArray<RefPtr<SourceSurface>>& aAdditionalImages,
+                                       const Point& aDestPoint,
+                                       const DrawOptions& aOptions)
+{
+  RefPtr<FilterNode> resultFilter =
+    FilterNodeGraphFromDescription(aDT, aFilter, aRenderRect,
+                                   aSourceGraphic, aSourceGraphicRect, aFillPaint, aFillPaintRect,
+                                   aStrokePaint, aStrokePaintRect, aAdditionalImages);
+  if (!resultFilter) {
+    gfxWarning() << "Filter is NULL.";
+    return;
+  }
+  aDT->DrawFilter(resultFilter, aRenderRect, aDestPoint, aOptions);
+}
+
+static nsIntRegion
+UnionOfRegions(const nsTArray<nsIntRegion>& aRegions)
+{
+  nsIntRegion result;
+  for (size_t i = 0; i < aRegions.Length(); i++) {
+    result.Or(result, aRegions[i]);
+  }
+  return result;
+}
+
+static int32_t
+InflateSizeForBlurStdDev(float aStdDev)
+{
+  double size = std::min(aStdDev, kMaxStdDeviation) * (3 * sqrt(2 * M_PI) / 4) * 1.5;
+  return uint32_t(floor(size + 0.5));
+}
+
+static nsIntRegion
+ResultChangeRegionForPrimitive(const FilterPrimitiveDescription& aDescription,
+                               const nsTArray<nsIntRegion>& aInputChangeRegions)
+{
+  const AttributeMap& atts = aDescription.Attributes();
+  switch (aDescription.Type()) {
+
+    case PrimitiveType::Empty:
+    case PrimitiveType::Flood:
+    case PrimitiveType::Turbulence:
+    case PrimitiveType::Image:
+      return nsIntRegion();
+
+    case PrimitiveType::Blend:
+    case PrimitiveType::Composite:
+    case PrimitiveType::Merge:
+      return UnionOfRegions(aInputChangeRegions);
+
+    case PrimitiveType::ColorMatrix:
+    case PrimitiveType::ComponentTransfer:
+    case PrimitiveType::ToAlpha:
+      return aInputChangeRegions[0];
+
+    case PrimitiveType::Morphology:
+    {
+      Size radii = atts.GetSize(eMorphologyRadii);
+      int32_t rx = clamped(int32_t(ceil(radii.width)), 0, kMorphologyMaxRadius);
+      int32_t ry = clamped(int32_t(ceil(radii.height)), 0, kMorphologyMaxRadius);
+      return aInputChangeRegions[0].Inflated(nsIntMargin(ry, rx, ry, rx));
+    }
+
+    case PrimitiveType::Tile:
+      return aDescription.PrimitiveSubregion();
+
+    case PrimitiveType::ConvolveMatrix:
+    {
+      if (atts.GetUint(eConvolveMatrixEdgeMode) != EDGE_MODE_NONE) {
+        return aDescription.PrimitiveSubregion();
+      }
+      Size kernelUnitLength = atts.GetSize(eConvolveMatrixKernelUnitLength);
+      IntSize kernelSize = atts.GetIntSize(eConvolveMatrixKernelSize);
+      IntPoint target = atts.GetIntPoint(eConvolveMatrixTarget);
+      nsIntMargin m(ceil(kernelUnitLength.width * (target.x)),
+                    ceil(kernelUnitLength.height * (target.y)),
+                    ceil(kernelUnitLength.width * (kernelSize.width - target.x - 1)),
+                    ceil(kernelUnitLength.height * (kernelSize.height - target.y - 1)));
+      return aInputChangeRegions[0].Inflated(m);
+    }
+
+    case PrimitiveType::Offset:
+    {
+      IntPoint offset = atts.GetIntPoint(eOffsetOffset);
+      return aInputChangeRegions[0].MovedBy(offset.x, offset.y);
+    }
+
+    case PrimitiveType::DisplacementMap:
+    {
+      int32_t scale = ceil(std::abs(atts.GetFloat(eDisplacementMapScale)));
+      return aInputChangeRegions[0].Inflated(nsIntMargin(scale, scale, scale, scale));
+    }
+
+    case PrimitiveType::GaussianBlur:
+    {
+      Size stdDeviation = atts.GetSize(eGaussianBlurStdDeviation);
+      int32_t dx = InflateSizeForBlurStdDev(stdDeviation.width);
+      int32_t dy = InflateSizeForBlurStdDev(stdDeviation.height);
+      return aInputChangeRegions[0].Inflated(nsIntMargin(dy, dx, dy, dx));
+    }
+
+    case PrimitiveType::DropShadow:
+    {
+      IntPoint offset = atts.GetIntPoint(eDropShadowOffset);
+      nsIntRegion offsetRegion = aInputChangeRegions[0].MovedBy(offset.x, offset.y);
+      Size stdDeviation = atts.GetSize(eDropShadowStdDeviation);
+      int32_t dx = InflateSizeForBlurStdDev(stdDeviation.width);
+      int32_t dy = InflateSizeForBlurStdDev(stdDeviation.height);
+      nsIntRegion blurRegion = offsetRegion.Inflated(nsIntMargin(dy, dx, dy, dx));
+      blurRegion.Or(blurRegion, aInputChangeRegions[0]);
+      return blurRegion;
+    }
+
+    case PrimitiveType::DiffuseLighting:
+    case PrimitiveType::SpecularLighting:
+    {
+      Size kernelUnitLength = atts.GetSize(eLightingKernelUnitLength);
+      int32_t dx = ceil(kernelUnitLength.width);
+      int32_t dy = ceil(kernelUnitLength.height);
+      return aInputChangeRegions[0].Inflated(nsIntMargin(dy, dx, dy, dx));
+    }
+
+    default:
+      return nsIntRegion();
+  }
+}
+
+/* static */ nsIntRegion
+FilterSupport::ComputeResultChangeRegion(const FilterDescription& aFilter,
+                                         const nsIntRegion& aSourceGraphicChange,
+                                         const nsIntRegion& aFillPaintChange,
+                                         const nsIntRegion& aStrokePaintChange)
+{
+  const nsTArray<FilterPrimitiveDescription>& primitives = aFilter.mPrimitives;
+  MOZ_RELEASE_ASSERT(!primitives.IsEmpty());
+
+  nsTArray<nsIntRegion> resultChangeRegions;
+
+  for (int32_t i = 0; i < int32_t(primitives.Length()); ++i) {
+    const FilterPrimitiveDescription& descr = primitives[i];
+
+    nsTArray<nsIntRegion> inputChangeRegions;
+    for (size_t j = 0; j < descr.NumberOfInputs(); j++) {
+      int32_t inputIndex = descr.InputPrimitiveIndex(j);
+      MOZ_ASSERT(inputIndex < i, "bad input index");
+      nsIntRegion inputChangeRegion =
+        ElementForIndex(inputIndex, resultChangeRegions,
+                        aSourceGraphicChange, aFillPaintChange,
+                        aStrokePaintChange);
+      inputChangeRegions.AppendElement(inputChangeRegion);
+    }
+    nsIntRegion changeRegion =
+      ResultChangeRegionForPrimitive(descr, inputChangeRegions);
+    changeRegion.And(changeRegion, descr.PrimitiveSubregion());
+    resultChangeRegions.AppendElement(changeRegion);
+  }
+
+  MOZ_RELEASE_ASSERT(!resultChangeRegions.IsEmpty());
+  return resultChangeRegions[resultChangeRegions.Length() - 1];
+}
+
+static float
+ResultOfZeroUnderTransferFunction(const AttributeMap& aFunctionAttributes)
+{
+  switch (aFunctionAttributes.GetUint(eComponentTransferFunctionType)) {
+    case SVG_FECOMPONENTTRANSFER_TYPE_TABLE:
+    {
+      const nsTArray<float>& tableValues =
+        aFunctionAttributes.GetFloats(eComponentTransferFunctionTableValues);
+      if (tableValues.Length() < 2) {
+        return 0.0f;
+      }
+      return tableValues[0];
+    }
+
+    case SVG_FECOMPONENTTRANSFER_TYPE_DISCRETE:
+    {
+      const nsTArray<float>& tableValues =
+        aFunctionAttributes.GetFloats(eComponentTransferFunctionTableValues);
+      if (tableValues.Length() < 1) {
+        return 0.0f;
+      }
+      return tableValues[0];
+    }
+
+    case SVG_FECOMPONENTTRANSFER_TYPE_LINEAR:
+      return aFunctionAttributes.GetFloat(eComponentTransferFunctionIntercept);
+
+    case SVG_FECOMPONENTTRANSFER_TYPE_GAMMA:
+      return aFunctionAttributes.GetFloat(eComponentTransferFunctionOffset);
+
+    case SVG_FECOMPONENTTRANSFER_TYPE_IDENTITY:
+    default:
+      return 0.0f;
+  }
+}
+
+nsIntRegion
+FilterSupport::PostFilterExtentsForPrimitive(const FilterPrimitiveDescription& aDescription,
+                                             const nsTArray<nsIntRegion>& aInputExtents)
+{
+  const AttributeMap& atts = aDescription.Attributes();
+  switch (aDescription.Type()) {
+
+    case PrimitiveType::Empty:
+      return IntRect();
+
+    case PrimitiveType::Composite:
+    {
+      uint32_t op = atts.GetUint(eCompositeOperator);
+      if (op == SVG_FECOMPOSITE_OPERATOR_ARITHMETIC) {
+        // The arithmetic composite primitive can draw outside the bounding
+        // box of its source images.
+        const nsTArray<float>& coefficients = atts.GetFloats(eCompositeCoefficients);
+        MOZ_ASSERT(coefficients.Length() == 4);
+
+        // The calculation is:
+        // r = c[0] * in[0] * in[1] + c[1] * in[0] + c[2] * in[1] + c[3]
+        nsIntRegion region;
+        if (coefficients[0] > 0.0f) {
+          region = aInputExtents[0].Intersect(aInputExtents[1]);
+        }
+        if (coefficients[1] > 0.0f) {
+          region.Or(region, aInputExtents[0]);
+        }
+        if (coefficients[2] > 0.0f) {
+          region.Or(region, aInputExtents[1]);
+        }
+        if (coefficients[3] > 0.0f) {
+          region = aDescription.PrimitiveSubregion();
+        }
+        return region;
+      }
+      if (op == SVG_FECOMPOSITE_OPERATOR_IN) {
+        return aInputExtents[0].Intersect(aInputExtents[1]);
+      }
+      return ResultChangeRegionForPrimitive(aDescription, aInputExtents);
+    }
+
+    case PrimitiveType::Flood:
+    {
+      if (atts.GetColor(eFloodColor).a == 0.0f) {
+        return IntRect();
+      }
+      return aDescription.PrimitiveSubregion();
+    }
+
+    case PrimitiveType::ColorMatrix:
+    {
+      if (atts.GetUint(eColorMatrixType) == (uint32_t)SVG_FECOLORMATRIX_TYPE_MATRIX) {
+        const nsTArray<float>& values = atts.GetFloats(eColorMatrixValues);
+        if (values.Length() == 20 && values[19] > 0.0f) {
+          return aDescription.PrimitiveSubregion();
+        }
+      }
+      return aInputExtents[0];
+    }
+
+    case PrimitiveType::ComponentTransfer:
+    {
+      AttributeMap functionAttributes =
+        atts.GetAttributeMap(eComponentTransferFunctionA);
+      if (ResultOfZeroUnderTransferFunction(functionAttributes) > 0.0f) {
+        return aDescription.PrimitiveSubregion();
+      }
+      return aInputExtents[0];
+    }
+
+    case PrimitiveType::Turbulence:
+    case PrimitiveType::Image:
+    case PrimitiveType::DiffuseLighting:
+    case PrimitiveType::SpecularLighting:
+    {
+      return aDescription.PrimitiveSubregion();
+    }
+
+    case PrimitiveType::Morphology:
+    {
+      uint32_t op = atts.GetUint(eMorphologyOperator);
+      if (op == SVG_OPERATOR_ERODE) {
+        return aInputExtents[0];
+      }
+      Size radii = atts.GetSize(eMorphologyRadii);
+      int32_t rx = clamped(int32_t(ceil(radii.width)), 0, kMorphologyMaxRadius);
+      int32_t ry = clamped(int32_t(ceil(radii.height)), 0, kMorphologyMaxRadius);
+      return aInputExtents[0].Inflated(nsIntMargin(ry, rx, ry, rx));
+    }
+
+    default:
+      return ResultChangeRegionForPrimitive(aDescription, aInputExtents);
+  }
+}
+
+/* static */ nsIntRegion
+FilterSupport::ComputePostFilterExtents(const FilterDescription& aFilter,
+                                        const nsIntRegion& aSourceGraphicExtents)
+{
+  const nsTArray<FilterPrimitiveDescription>& primitives = aFilter.mPrimitives;
+  MOZ_RELEASE_ASSERT(!primitives.IsEmpty());
+  nsTArray<nsIntRegion> postFilterExtents;
+
+  for (int32_t i = 0; i < int32_t(primitives.Length()); ++i) {
+    const FilterPrimitiveDescription& descr = primitives[i];
+    nsIntRegion filterSpace = descr.FilterSpaceBounds();
+
+    nsTArray<nsIntRegion> inputExtents;
+    for (size_t j = 0; j < descr.NumberOfInputs(); j++) {
+      int32_t inputIndex = descr.InputPrimitiveIndex(j);
+      MOZ_ASSERT(inputIndex < i, "bad input index");
+      nsIntRegion inputExtent =
+        ElementForIndex(inputIndex, postFilterExtents,
+                        aSourceGraphicExtents, filterSpace, filterSpace);
+      inputExtents.AppendElement(inputExtent);
+    }
+    nsIntRegion extent = PostFilterExtentsForPrimitive(descr, inputExtents);
+    extent.And(extent, descr.PrimitiveSubregion());
+    postFilterExtents.AppendElement(extent);
+  }
+
+  MOZ_RELEASE_ASSERT(!postFilterExtents.IsEmpty());
+  return postFilterExtents[postFilterExtents.Length() - 1];
+}
+
+static nsIntRegion
+SourceNeededRegionForPrimitive(const FilterPrimitiveDescription& aDescription,
+                               const nsIntRegion& aResultNeededRegion,
+                               int32_t aInputIndex)
+{
+  const AttributeMap& atts = aDescription.Attributes();
+  switch (aDescription.Type()) {
+
+    case PrimitiveType::Flood:
+    case PrimitiveType::Turbulence:
+    case PrimitiveType::Image:
+      MOZ_CRASH("GFX: this shouldn't be called for filters without inputs");
+      return nsIntRegion();
+
+    case PrimitiveType::Empty:
+      return nsIntRegion();
+
+    case PrimitiveType::Blend:
+    case PrimitiveType::Composite:
+    case PrimitiveType::Merge:
+    case PrimitiveType::ColorMatrix:
+    case PrimitiveType::ComponentTransfer:
+    case PrimitiveType::ToAlpha:
+      return aResultNeededRegion;
+
+    case PrimitiveType::Morphology:
+    {
+      Size radii = atts.GetSize(eMorphologyRadii);
+      int32_t rx = clamped(int32_t(ceil(radii.width)), 0, kMorphologyMaxRadius);
+      int32_t ry = clamped(int32_t(ceil(radii.height)), 0, kMorphologyMaxRadius);
+      return aResultNeededRegion.Inflated(nsIntMargin(ry, rx, ry, rx));
+    }
+
+    case PrimitiveType::Tile:
+      return IntRect(INT32_MIN/2, INT32_MIN/2, INT32_MAX, INT32_MAX);
+
+    case PrimitiveType::ConvolveMatrix:
+    {
+      Size kernelUnitLength = atts.GetSize(eConvolveMatrixKernelUnitLength);
+      IntSize kernelSize = atts.GetIntSize(eConvolveMatrixKernelSize);
+      IntPoint target = atts.GetIntPoint(eConvolveMatrixTarget);
+      nsIntMargin m(ceil(kernelUnitLength.width * (kernelSize.width - target.x - 1)),
+                    ceil(kernelUnitLength.height * (kernelSize.height - target.y - 1)),
+                    ceil(kernelUnitLength.width * (target.x)),
+                    ceil(kernelUnitLength.height * (target.y)));
+      return aResultNeededRegion.Inflated(m);
+    }
+
+    case PrimitiveType::Offset:
+    {
+      IntPoint offset = atts.GetIntPoint(eOffsetOffset);
+      return aResultNeededRegion.MovedBy(-nsIntPoint(offset.x, offset.y));
+    }
+
+    case PrimitiveType::DisplacementMap:
+    {
+      if (aInputIndex == 1) {
+        return aResultNeededRegion;
+      }
+      int32_t scale = ceil(std::abs(atts.GetFloat(eDisplacementMapScale)));
+      return aResultNeededRegion.Inflated(nsIntMargin(scale, scale, scale, scale));
+    }
+
+    case PrimitiveType::GaussianBlur:
+    {
+      Size stdDeviation = atts.GetSize(eGaussianBlurStdDeviation);
+      int32_t dx = InflateSizeForBlurStdDev(stdDeviation.width);
+      int32_t dy = InflateSizeForBlurStdDev(stdDeviation.height);
+      return aResultNeededRegion.Inflated(nsIntMargin(dy, dx, dy, dx));
+    }
+
+    case PrimitiveType::DropShadow:
+    {
+      IntPoint offset = atts.GetIntPoint(eDropShadowOffset);
+      nsIntRegion offsetRegion =
+        aResultNeededRegion.MovedBy(-nsIntPoint(offset.x, offset.y));
+      Size stdDeviation = atts.GetSize(eDropShadowStdDeviation);
+      int32_t dx = InflateSizeForBlurStdDev(stdDeviation.width);
+      int32_t dy = InflateSizeForBlurStdDev(stdDeviation.height);
+      nsIntRegion blurRegion = offsetRegion.Inflated(nsIntMargin(dy, dx, dy, dx));
+      blurRegion.Or(blurRegion, aResultNeededRegion);
+      return blurRegion;
+    }
+
+    case PrimitiveType::DiffuseLighting:
+    case PrimitiveType::SpecularLighting:
+    {
+      Size kernelUnitLength = atts.GetSize(eLightingKernelUnitLength);
+      int32_t dx = ceil(kernelUnitLength.width);
+      int32_t dy = ceil(kernelUnitLength.height);
+      return aResultNeededRegion.Inflated(nsIntMargin(dy, dx, dy, dx));
+    }
+
+    default:
+      return nsIntRegion();
+  }
+
+}
+
+/* static */ void
+FilterSupport::ComputeSourceNeededRegions(const FilterDescription& aFilter,
+                                          const nsIntRegion& aResultNeededRegion,
+                                          nsIntRegion& aSourceGraphicNeededRegion,
+                                          nsIntRegion& aFillPaintNeededRegion,
+                                          nsIntRegion& aStrokePaintNeededRegion)
+{
+  const nsTArray<FilterPrimitiveDescription>& primitives = aFilter.mPrimitives;
+  MOZ_ASSERT(!primitives.IsEmpty());
+  if (primitives.IsEmpty()) {
+    return;
+  }
+
+  nsTArray<nsIntRegion> primitiveNeededRegions;
+  primitiveNeededRegions.AppendElements(primitives.Length());
+
+  primitiveNeededRegions[primitives.Length() - 1] = aResultNeededRegion;
+
+  for (int32_t i = primitives.Length() - 1; i >= 0; --i) {
+    const FilterPrimitiveDescription& descr = primitives[i];
+    nsIntRegion neededRegion = primitiveNeededRegions[i];
+    neededRegion.And(neededRegion, descr.PrimitiveSubregion());
+
+    for (size_t j = 0; j < descr.NumberOfInputs(); j++) {
+      int32_t inputIndex = descr.InputPrimitiveIndex(j);
+      MOZ_ASSERT(inputIndex < i, "bad input index");
+      nsIntRegion* inputNeededRegion = const_cast<nsIntRegion*>(
+        &ElementForIndex(inputIndex, primitiveNeededRegions,
+                         aSourceGraphicNeededRegion,
+                         aFillPaintNeededRegion, aStrokePaintNeededRegion));
+      inputNeededRegion->Or(*inputNeededRegion,
+        SourceNeededRegionForPrimitive(descr, neededRegion, j));
+    }
+  }
+
+  // Clip original SourceGraphic to first filter region.
+  const FilterPrimitiveDescription& firstDescr = primitives[0];
+  aSourceGraphicNeededRegion.And(aSourceGraphicNeededRegion,
+                                 firstDescr.FilterSpaceBounds());
+}
+
+// FilterPrimitiveDescription
+
+FilterPrimitiveDescription::FilterPrimitiveDescription()
+ : mType(PrimitiveType::Empty)
+ , mOutputColorSpace(ColorSpace::SRGB)
+ , mIsTainted(false)
+{
+}
+
+FilterPrimitiveDescription::FilterPrimitiveDescription(PrimitiveType aType)
+ : mType(aType)
+ , mOutputColorSpace(ColorSpace::SRGB)
+ , mIsTainted(false)
+{
+}
+
+FilterPrimitiveDescription::FilterPrimitiveDescription(const FilterPrimitiveDescription& aOther)
+ : mType(aOther.mType)
+ , mAttributes(aOther.mAttributes)
+ , mInputPrimitives(aOther.mInputPrimitives)
+ , mFilterPrimitiveSubregion(aOther.mFilterPrimitiveSubregion)
+ , mFilterSpaceBounds(aOther.mFilterSpaceBounds)
+ , mInputColorSpaces(aOther.mInputColorSpaces)
+ , mOutputColorSpace(aOther.mOutputColorSpace)
+ , mIsTainted(aOther.mIsTainted)
+{
+}
+
+FilterPrimitiveDescription&
+FilterPrimitiveDescription::operator=(const FilterPrimitiveDescription& aOther)
+{
+  if (this != &aOther) {
+    mType = aOther.mType;
+    mAttributes = aOther.mAttributes;
+    mInputPrimitives = aOther.mInputPrimitives;
+    mFilterPrimitiveSubregion = aOther.mFilterPrimitiveSubregion;
+    mFilterSpaceBounds = aOther.mFilterSpaceBounds;
+    mInputColorSpaces = aOther.mInputColorSpaces;
+    mOutputColorSpace = aOther.mOutputColorSpace;
+    mIsTainted = aOther.mIsTainted;
+  }
+  return *this;
+}
+
+bool
+FilterPrimitiveDescription::operator==(const FilterPrimitiveDescription& aOther) const
+{
+  return mType == aOther.mType &&
+    mFilterPrimitiveSubregion.IsEqualInterior(aOther.mFilterPrimitiveSubregion) &&
+    mFilterSpaceBounds.IsEqualInterior(aOther.mFilterSpaceBounds) &&
+    mOutputColorSpace == aOther.mOutputColorSpace &&
+    mIsTainted == aOther.mIsTainted &&
+    mInputPrimitives == aOther.mInputPrimitives &&
+    mInputColorSpaces == aOther.mInputColorSpaces &&
+    mAttributes == aOther.mAttributes;
+}
+
+// FilterDescription
+
+bool
+FilterDescription::operator==(const FilterDescription& aOther) const
+{
+  return mPrimitives == aOther.mPrimitives;
+}
+
+// AttributeMap
+
+// A class that wraps different types for easy storage in a hashtable. Only
+// used by AttributeMap.
+struct FilterAttribute {
+  FilterAttribute(const FilterAttribute& aOther);
+  ~FilterAttribute();
+
+  bool operator==(const FilterAttribute& aOther) const;
+  bool operator!=(const FilterAttribute& aOther) const
+  {
+    return !(*this == aOther);
+  }
+
+  AttributeType Type() const { return mType; }
+
+#define MAKE_CONSTRUCTOR_AND_ACCESSOR_BASIC(type, typeLabel)   \
+  explicit FilterAttribute(type aValue)                        \
+   : mType(AttributeType::e##typeLabel), m##typeLabel(aValue)  \
+  {}                                                           \
+  type As##typeLabel() {                                       \
+    MOZ_ASSERT(mType == AttributeType::e##typeLabel);          \
+    return m##typeLabel;                                       \
+  }
+
+#define MAKE_CONSTRUCTOR_AND_ACCESSOR_CLASS(className)         \
+  explicit FilterAttribute(const className& aValue)            \
+   : mType(AttributeType::e##className), m##className(new className(aValue)) \
+  {}                                                           \
+  className As##className() {                                  \
+    MOZ_ASSERT(mType == AttributeType::e##className);          \
+    return *m##className;                                      \
+  }
+
+  MAKE_CONSTRUCTOR_AND_ACCESSOR_BASIC(bool, Bool)
+  MAKE_CONSTRUCTOR_AND_ACCESSOR_BASIC(uint32_t, Uint)
+  MAKE_CONSTRUCTOR_AND_ACCESSOR_BASIC(float, Float)
+  MAKE_CONSTRUCTOR_AND_ACCESSOR_CLASS(Size)
+  MAKE_CONSTRUCTOR_AND_ACCESSOR_CLASS(IntSize)
+  MAKE_CONSTRUCTOR_AND_ACCESSOR_CLASS(IntPoint)
+  MAKE_CONSTRUCTOR_AND_ACCESSOR_CLASS(Matrix)
+  MAKE_CONSTRUCTOR_AND_ACCESSOR_CLASS(Matrix5x4)
+  MAKE_CONSTRUCTOR_AND_ACCESSOR_CLASS(Point3D)
+  MAKE_CONSTRUCTOR_AND_ACCESSOR_CLASS(Color)
+  MAKE_CONSTRUCTOR_AND_ACCESSOR_CLASS(AttributeMap)
+
+#undef MAKE_CONSTRUCTOR_AND_ACCESSOR_BASIC
+#undef MAKE_CONSTRUCTOR_AND_ACCESSOR_CLASS
+
+  FilterAttribute(const float* aValue, uint32_t aLength)
+   : mType(AttributeType::eFloats)
+  {
+    mFloats = new nsTArray<float>();
+    mFloats->AppendElements(aValue, aLength);
+  }
+
+  const nsTArray<float>& AsFloats() const {
+    MOZ_ASSERT(mType == AttributeType::eFloats);
+    return *mFloats;
+  }
+
+private:
+  const AttributeType mType;
+
+  union {
+    bool mBool;
+    uint32_t mUint;
+    float mFloat;
+    Size* mSize;
+    IntSize* mIntSize;
+    IntPoint* mIntPoint;
+    Matrix* mMatrix;
+    Matrix5x4* mMatrix5x4;
+    Point3D* mPoint3D;
+    Color* mColor;
+    AttributeMap* mAttributeMap;
+    nsTArray<float>* mFloats;
+  };
+};
+
+FilterAttribute::FilterAttribute(const FilterAttribute& aOther)
+ : mType(aOther.mType)
+{
+  switch (mType) {
+    case AttributeType::eBool:
+      mBool = aOther.mBool;
+      break;
+    case AttributeType::eUint:
+      mUint = aOther.mUint;
+      break;
+    case AttributeType::eFloat:
+      mFloat = aOther.mFloat;
+      break;
+
+#define HANDLE_CLASS(className)                            \
+    case AttributeType::e##className:                      \
+      m##className = new className(*aOther.m##className);  \
+      break;
+
+    HANDLE_CLASS(Size)
+    HANDLE_CLASS(IntSize)
+    HANDLE_CLASS(IntPoint)
+    HANDLE_CLASS(Matrix)
+    HANDLE_CLASS(Matrix5x4)
+    HANDLE_CLASS(Point3D)
+    HANDLE_CLASS(Color)
+    HANDLE_CLASS(AttributeMap)
+
+#undef HANDLE_CLASS
+
+    case AttributeType::eFloats:
+      mFloats = new nsTArray<float>(*aOther.mFloats);
+      break;
+    case AttributeType::Max:
+      break;
+  }
+}
+
+FilterAttribute::~FilterAttribute() {
+  switch (mType) {
+    case AttributeType::Max:
+    case AttributeType::eBool:
+    case AttributeType::eUint:
+    case AttributeType::eFloat:
+      break;
+
+#define HANDLE_CLASS(className)                            \
+    case AttributeType::e##className:                      \
+      delete m##className;                                 \
+      break;
+
+    HANDLE_CLASS(Size)
+    HANDLE_CLASS(IntSize)
+    HANDLE_CLASS(IntPoint)
+    HANDLE_CLASS(Matrix)
+    HANDLE_CLASS(Matrix5x4)
+    HANDLE_CLASS(Point3D)
+    HANDLE_CLASS(Color)
+    HANDLE_CLASS(AttributeMap)
+
+#undef HANDLE_CLASS
+
+    case AttributeType::eFloats:
+      delete mFloats;
+      break;
+  }
+}
+
+bool
+FilterAttribute::operator==(const FilterAttribute& aOther) const
+{
+  if (mType != aOther.mType) {
+    return false;
+  }
+
+  switch (mType) {
+
+#define HANDLE_TYPE(typeName)                              \
+    case AttributeType::e##typeName:                       \
+      return m##typeName == aOther.m##typeName;
+
+    HANDLE_TYPE(Bool)
+    HANDLE_TYPE(Uint)
+    HANDLE_TYPE(Float)
+    HANDLE_TYPE(Size)
+    HANDLE_TYPE(IntSize)
+    HANDLE_TYPE(IntPoint)
+    HANDLE_TYPE(Matrix)
+    HANDLE_TYPE(Matrix5x4)
+    HANDLE_TYPE(Point3D)
+    HANDLE_TYPE(Color)
+    HANDLE_TYPE(AttributeMap)
+    HANDLE_TYPE(Floats)
+
+#undef HANDLE_TYPE
+
+    default:
+      return false;
+  }
+}
+
+typedef FilterAttribute Attribute;
+
+AttributeMap::AttributeMap()
+{
+}
+
+AttributeMap::~AttributeMap()
+{
+}
+
+AttributeMap::AttributeMap(const AttributeMap& aOther)
+{
+  for (auto iter = aOther.mMap.Iter(); !iter.Done(); iter.Next()) {
+    const uint32_t& attributeName = iter.Key();
+    Attribute* attribute = iter.UserData();
+    mMap.Put(attributeName, new Attribute(*attribute));
+  }
+}
+
+AttributeMap&
+AttributeMap::operator=(const AttributeMap& aOther)
+{
+  if (this != &aOther) {
+    mMap.Clear();
+    for (auto iter = aOther.mMap.Iter(); !iter.Done(); iter.Next()) {
+      const uint32_t& attributeName = iter.Key();
+      Attribute* attribute = iter.UserData();
+      mMap.Put(attributeName, new Attribute(*attribute));
+    }
+  }
+  return *this;
+}
+
+bool
+AttributeMap::operator==(const AttributeMap& aOther) const
+{
+  if (mMap.Count() != aOther.mMap.Count()) {
+    return false;
+  }
+
+  for (auto iter = aOther.mMap.Iter(); !iter.Done(); iter.Next()) {
+    const uint32_t& attributeName = iter.Key();
+    Attribute* attribute = iter.UserData();
+    Attribute* matchingAttribute = mMap.Get(attributeName);
+    if (!matchingAttribute || *matchingAttribute != *attribute) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+uint32_t
+AttributeMap::Count() const
+{
+  return mMap.Count();
+}
+
+nsClassHashtable<nsUint32HashKey, FilterAttribute>::Iterator
+AttributeMap::ConstIter() const
+{
+  return mMap.ConstIter();
+}
+
+/* static */ AttributeType
+AttributeMap::GetType(FilterAttribute* aAttribute)
+{
+  return aAttribute->Type();
+}
+
+#define MAKE_ATTRIBUTE_HANDLERS_BASIC(type, typeLabel, defaultValue) \
+  type                                                               \
+  AttributeMap::Get##typeLabel(AttributeName aName) const {          \
+    Attribute* value = mMap.Get(aName);                              \
+    return value ? value->As##typeLabel() : defaultValue;            \
+  }                                                                  \
+  void                                                               \
+  AttributeMap::Set(AttributeName aName, type aValue) {              \
+    mMap.Remove(aName);                                              \
+    mMap.Put(aName, new Attribute(aValue));                          \
+  }
+
+#define MAKE_ATTRIBUTE_HANDLERS_CLASS(className)                     \
+  className                                                          \
+  AttributeMap::Get##className(AttributeName aName) const {          \
+    Attribute* value = mMap.Get(aName);                              \
+    return value ? value->As##className() : className();             \
+  }                                                                  \
+  void                                                               \
+  AttributeMap::Set(AttributeName aName, const className& aValue) {  \
+    mMap.Remove(aName);                                              \
+    mMap.Put(aName, new Attribute(aValue));                          \
+  }
+
+MAKE_ATTRIBUTE_HANDLERS_BASIC(bool, Bool, false)
+MAKE_ATTRIBUTE_HANDLERS_BASIC(uint32_t, Uint, 0)
+MAKE_ATTRIBUTE_HANDLERS_BASIC(float, Float, 0)
+MAKE_ATTRIBUTE_HANDLERS_CLASS(Size)
+MAKE_ATTRIBUTE_HANDLERS_CLASS(IntSize)
+MAKE_ATTRIBUTE_HANDLERS_CLASS(IntPoint)
+MAKE_ATTRIBUTE_HANDLERS_CLASS(Matrix)
+MAKE_ATTRIBUTE_HANDLERS_CLASS(Matrix5x4)
+MAKE_ATTRIBUTE_HANDLERS_CLASS(Point3D)
+MAKE_ATTRIBUTE_HANDLERS_CLASS(Color)
+MAKE_ATTRIBUTE_HANDLERS_CLASS(AttributeMap)
+
+#undef MAKE_ATTRIBUTE_HANDLERS_BASIC
+#undef MAKE_ATTRIBUTE_HANDLERS_CLASS
+
+const nsTArray<float>&
+AttributeMap::GetFloats(AttributeName aName) const
+{
+  Attribute* value = mMap.Get(aName);
+  if (!value) {
+    value = new Attribute(nullptr, 0);
+    mMap.Put(aName, value);
+  }
+  return value->AsFloats();
+}
+
+void
+AttributeMap::Set(AttributeName aName, const float* aValues, int32_t aLength)
+{
+  mMap.Remove(aName);
+  mMap.Put(aName, new Attribute(aValues, aLength));
+}
+
+} // namespace gfx
+} // namespace mozilla
diff --git a/gfx/src/FilterSupport.h b/gfx/src/FilterSupport.h
new file mode 100644
index 000000000..96a43d7cb
--- /dev/null
+++ b/gfx/src/FilterSupport.h
@@ -0,0 +1,479 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef __FilterSupport_h
+#define __FilterSupport_h
+
+#include "mozilla/Attributes.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/gfx/Rect.h"
+#include "mozilla/gfx/Matrix.h"
+#include "mozilla/gfx/2D.h"
+#include "nsClassHashtable.h"
+#include "nsTArray.h"
+#include "nsRegion.h"
+
+namespace mozilla {
+namespace gfx {
+
+// Morphology Operators
+const unsigned short SVG_OPERATOR_UNKNOWN = 0;
+const unsigned short SVG_OPERATOR_ERODE = 1;
+const unsigned short SVG_OPERATOR_DILATE = 2;
+
+// ColorMatrix types
+const unsigned short SVG_FECOLORMATRIX_TYPE_UNKNOWN = 0;
+const unsigned short SVG_FECOLORMATRIX_TYPE_MATRIX = 1;
+const unsigned short SVG_FECOLORMATRIX_TYPE_SATURATE = 2;
+const unsigned short SVG_FECOLORMATRIX_TYPE_HUE_ROTATE = 3;
+const unsigned short SVG_FECOLORMATRIX_TYPE_LUMINANCE_TO_ALPHA = 4;
+// ColorMatrix types for CSS filters
+const unsigned short SVG_FECOLORMATRIX_TYPE_SEPIA = 5;
+
+// ComponentTransfer types
+const unsigned short SVG_FECOMPONENTTRANSFER_TYPE_UNKNOWN  = 0;
+const unsigned short SVG_FECOMPONENTTRANSFER_TYPE_IDENTITY = 1;
+const unsigned short SVG_FECOMPONENTTRANSFER_TYPE_TABLE    = 2;
+const unsigned short SVG_FECOMPONENTTRANSFER_TYPE_DISCRETE = 3;
+const unsigned short SVG_FECOMPONENTTRANSFER_TYPE_LINEAR   = 4;
+const unsigned short SVG_FECOMPONENTTRANSFER_TYPE_GAMMA    = 5;
+
+// Blend Mode Values
+const unsigned short SVG_FEBLEND_MODE_UNKNOWN = 0;
+const unsigned short SVG_FEBLEND_MODE_NORMAL = 1;
+const unsigned short SVG_FEBLEND_MODE_MULTIPLY = 2;
+const unsigned short SVG_FEBLEND_MODE_SCREEN = 3;
+const unsigned short SVG_FEBLEND_MODE_DARKEN = 4;
+const unsigned short SVG_FEBLEND_MODE_LIGHTEN = 5;
+const unsigned short SVG_FEBLEND_MODE_OVERLAY = 6;
+const unsigned short SVG_FEBLEND_MODE_COLOR_DODGE = 7;
+const unsigned short SVG_FEBLEND_MODE_COLOR_BURN = 8;
+const unsigned short SVG_FEBLEND_MODE_HARD_LIGHT = 9;
+const unsigned short SVG_FEBLEND_MODE_SOFT_LIGHT = 10;
+const unsigned short SVG_FEBLEND_MODE_DIFFERENCE = 11;
+const unsigned short SVG_FEBLEND_MODE_EXCLUSION = 12;
+const unsigned short SVG_FEBLEND_MODE_HUE = 13;
+const unsigned short SVG_FEBLEND_MODE_SATURATION = 14;
+const unsigned short SVG_FEBLEND_MODE_COLOR = 15;
+const unsigned short SVG_FEBLEND_MODE_LUMINOSITY = 16;
+
+// Edge Mode Values
+const unsigned short SVG_EDGEMODE_UNKNOWN = 0;
+const unsigned short SVG_EDGEMODE_DUPLICATE = 1;
+const unsigned short SVG_EDGEMODE_WRAP = 2;
+const unsigned short SVG_EDGEMODE_NONE = 3;
+
+// Channel Selectors
+const unsigned short SVG_CHANNEL_UNKNOWN = 0;
+const unsigned short SVG_CHANNEL_R = 1;
+const unsigned short SVG_CHANNEL_G = 2;
+const unsigned short SVG_CHANNEL_B = 3;
+const unsigned short SVG_CHANNEL_A = 4;
+
+// Turbulence Types
+const unsigned short SVG_TURBULENCE_TYPE_UNKNOWN = 0;
+const unsigned short SVG_TURBULENCE_TYPE_FRACTALNOISE = 1;
+const unsigned short SVG_TURBULENCE_TYPE_TURBULENCE = 2;
+
+// Composite Operators
+const unsigned short SVG_FECOMPOSITE_OPERATOR_UNKNOWN = 0;
+const unsigned short SVG_FECOMPOSITE_OPERATOR_OVER = 1;
+const unsigned short SVG_FECOMPOSITE_OPERATOR_IN = 2;
+const unsigned short SVG_FECOMPOSITE_OPERATOR_OUT = 3;
+const unsigned short SVG_FECOMPOSITE_OPERATOR_ATOP = 4;
+const unsigned short SVG_FECOMPOSITE_OPERATOR_XOR = 5;
+const unsigned short SVG_FECOMPOSITE_OPERATOR_ARITHMETIC = 6;
+
+enum AttributeName {
+  eBlendBlendmode = 0,
+  eMorphologyRadii,
+  eMorphologyOperator,
+  eColorMatrixType,
+  eColorMatrixValues,
+  eFloodColor,
+  eTileSourceRect,
+  eComponentTransferFunctionR,
+  eComponentTransferFunctionG,
+  eComponentTransferFunctionB,
+  eComponentTransferFunctionA,
+  eComponentTransferFunctionType,
+  eComponentTransferFunctionTableValues,
+  eComponentTransferFunctionSlope,
+  eComponentTransferFunctionIntercept,
+  eComponentTransferFunctionAmplitude,
+  eComponentTransferFunctionExponent,
+  eComponentTransferFunctionOffset,
+  eConvolveMatrixKernelSize,
+  eConvolveMatrixKernelMatrix,
+  eConvolveMatrixDivisor,
+  eConvolveMatrixBias,
+  eConvolveMatrixTarget,
+  eConvolveMatrixEdgeMode,
+  eConvolveMatrixKernelUnitLength,
+  eConvolveMatrixPreserveAlpha,
+  eOffsetOffset,
+  eDropShadowStdDeviation,
+  eDropShadowOffset,
+  eDropShadowColor,
+  eDisplacementMapScale,
+  eDisplacementMapXChannel,
+  eDisplacementMapYChannel,
+  eTurbulenceOffset,
+  eTurbulenceBaseFrequency,
+  eTurbulenceNumOctaves,
+  eTurbulenceSeed,
+  eTurbulenceStitchable,
+  eTurbulenceType,
+  eCompositeOperator,
+  eCompositeCoefficients,
+  eGaussianBlurStdDeviation,
+  eLightingLight,
+  eLightingSurfaceScale,
+  eLightingKernelUnitLength,
+  eLightingColor,
+  eDiffuseLightingDiffuseConstant,
+  eSpecularLightingSpecularConstant,
+  eSpecularLightingSpecularExponent,
+  eLightType,
+  eLightTypeNone,
+  eLightTypePoint,
+  eLightTypeSpot,
+  eLightTypeDistant,
+  ePointLightPosition,
+  eSpotLightPosition,
+  eSpotLightPointsAt,
+  eSpotLightFocus,
+  eSpotLightLimitingConeAngle,
+  eDistantLightAzimuth,
+  eDistantLightElevation,
+  eImageInputIndex,
+  eImageFilter,
+  eImageNativeSize,
+  eImageSubregion,
+  eImageTransform,
+  eLastAttributeName
+};
+
+class DrawTarget;
+class SourceSurface;
+struct FilterAttribute;
+
+enum class AttributeType {
+  eBool,
+  eUint,
+  eFloat,
+  eSize,
+  eIntSize,
+  eIntPoint,
+  eMatrix,
+  eMatrix5x4,
+  ePoint3D,
+  eColor,
+  eAttributeMap,
+  eFloats,
+  Max
+};
+
+// Limits
+const float kMaxStdDeviation = 500;
+
+// A class that stores values of different types, keyed by an attribute name.
+// The Get*() methods assert that they're called for the same type that the
+// attribute was Set() with.
+// AttributeMaps can be nested because AttributeMap is a valid attribute type.
+class AttributeMap final {
+public:
+  AttributeMap();
+  AttributeMap(const AttributeMap& aOther);
+  AttributeMap& operator=(const AttributeMap& aOther);
+  bool operator==(const AttributeMap& aOther) const;
+  bool operator!=(const AttributeMap& aOther) const
+  {
+    return !(*this == aOther);
+  }
+  ~AttributeMap();
+
+  void Set(AttributeName aName, bool aValue);
+  void Set(AttributeName aName, uint32_t aValue);
+  void Set(AttributeName aName, float aValue);
+  void Set(AttributeName aName, const Size& aValue);
+  void Set(AttributeName aName, const IntSize& aValue);
+  void Set(AttributeName aName, const IntPoint& aValue);
+  void Set(AttributeName aName, const Matrix& aValue);
+  void Set(AttributeName aName, const Matrix5x4& aValue);
+  void Set(AttributeName aName, const Point3D& aValue);
+  void Set(AttributeName aName, const Color& aValue);
+  void Set(AttributeName aName, const AttributeMap& aValue);
+  void Set(AttributeName aName, const float* aValues, int32_t aLength);
+
+  bool GetBool(AttributeName aName) const;
+  uint32_t GetUint(AttributeName aName) const;
+  float GetFloat(AttributeName aName) const;
+  Size GetSize(AttributeName aName) const;
+  IntSize GetIntSize(AttributeName aName) const;
+  IntPoint GetIntPoint(AttributeName aName) const;
+  Matrix GetMatrix(AttributeName aName) const;
+  Matrix5x4 GetMatrix5x4(AttributeName aName) const;
+  Point3D GetPoint3D(AttributeName aName) const;
+  Color GetColor(AttributeName aName) const;
+  AttributeMap GetAttributeMap(AttributeName aName) const;
+  const nsTArray<float>& GetFloats(AttributeName aName) const;
+
+  uint32_t Count() const;
+
+  nsClassHashtable<nsUint32HashKey, FilterAttribute>::Iterator ConstIter() const;
+
+  static AttributeType GetType(FilterAttribute* aAttribute);
+
+private:
+  mutable nsClassHashtable<nsUint32HashKey, FilterAttribute>  mMap;
+};
+
+enum class ColorSpace {
+  SRGB,
+  LinearRGB,
+  Max
+};
+
+enum class AlphaModel {
+  Unpremultiplied,
+  Premultiplied
+};
+
+class ColorModel {
+public:
+  static ColorModel PremulSRGB()
+  {
+    return ColorModel(ColorSpace::SRGB, AlphaModel::Premultiplied);
+  }
+
+  ColorModel(ColorSpace aColorSpace, AlphaModel aAlphaModel) :
+    mColorSpace(aColorSpace), mAlphaModel(aAlphaModel) {}
+  ColorModel() :
+    mColorSpace(ColorSpace::SRGB), mAlphaModel(AlphaModel::Premultiplied) {}
+  bool operator==(const ColorModel& aOther) const {
+    return mColorSpace == aOther.mColorSpace &&
+           mAlphaModel == aOther.mAlphaModel;
+  }
+
+  // Used to index FilterCachedColorModels::mFilterForColorModel.
+  uint8_t ToIndex() const
+  {
+    return (uint8_t(mColorSpace) << 1) + uint8_t(mAlphaModel);
+  }
+
+  ColorSpace mColorSpace;
+  AlphaModel mAlphaModel;
+};
+
+enum class PrimitiveType {
+  Empty = 0,
+  Blend,
+  Morphology,
+  ColorMatrix,
+  Flood,
+  Tile,
+  ComponentTransfer,
+  ConvolveMatrix,
+  Offset,
+  DisplacementMap,
+  Turbulence,
+  Composite,
+  Merge,
+  Image,
+  GaussianBlur,
+  DropShadow,
+  DiffuseLighting,
+  SpecularLighting,
+  ToAlpha,
+  Max
+};
+
+/**
+ * A data structure to carry attributes for a given primitive that's part of a
+ * filter. Will be serializable via IPDL, so it must not contain complex
+ * functionality.
+ * Used as part of a FilterDescription.
+ */
+class FilterPrimitiveDescription final {
+public:
+  enum {
+    kPrimitiveIndexSourceGraphic = -1,
+    kPrimitiveIndexSourceAlpha = -2,
+    kPrimitiveIndexFillPaint = -3,
+    kPrimitiveIndexStrokePaint = -4
+  };
+
+  FilterPrimitiveDescription();
+  explicit FilterPrimitiveDescription(PrimitiveType aType);
+  FilterPrimitiveDescription(const FilterPrimitiveDescription& aOther);
+  FilterPrimitiveDescription& operator=(const FilterPrimitiveDescription& aOther);
+
+  PrimitiveType Type() const { return mType; }
+  void SetType(PrimitiveType aType) { mType = aType; }
+  const AttributeMap& Attributes() const { return mAttributes; }
+  AttributeMap& Attributes() { return mAttributes; }
+
+  IntRect PrimitiveSubregion() const { return mFilterPrimitiveSubregion; }
+  IntRect FilterSpaceBounds() const { return mFilterSpaceBounds; }
+  bool IsTainted() const { return mIsTainted; }
+
+  size_t NumberOfInputs() const { return mInputPrimitives.Length(); }
+  int32_t InputPrimitiveIndex(size_t aInputIndex) const
+  {
+    return aInputIndex < mInputPrimitives.Length() ?
+      mInputPrimitives[aInputIndex] : 0;
+  }
+
+  ColorSpace InputColorSpace(size_t aInputIndex) const
+  {
+    return aInputIndex < mInputColorSpaces.Length() ?
+      mInputColorSpaces[aInputIndex] : ColorSpace();
+  }
+
+  ColorSpace OutputColorSpace() const { return mOutputColorSpace; }
+
+  void SetPrimitiveSubregion(const IntRect& aRect)
+  {
+    mFilterPrimitiveSubregion = aRect;
+  }
+
+  void SetFilterSpaceBounds(const IntRect& aRect)
+  {
+    mFilterSpaceBounds = aRect;
+  }
+
+  void SetIsTainted(bool aIsTainted)
+  {
+    mIsTainted = aIsTainted;
+  }
+
+  void SetInputPrimitive(size_t aInputIndex, int32_t aInputPrimitiveIndex)
+  {
+    mInputPrimitives.EnsureLengthAtLeast(aInputIndex + 1);
+    mInputPrimitives[aInputIndex] = aInputPrimitiveIndex;
+  }
+
+  void SetInputColorSpace(size_t aInputIndex, ColorSpace aColorSpace)
+  {
+    mInputColorSpaces.EnsureLengthAtLeast(aInputIndex + 1);
+    mInputColorSpaces[aInputIndex] = aColorSpace;
+  }
+
+  void SetOutputColorSpace(const ColorSpace& aColorSpace)
+  {
+    mOutputColorSpace = aColorSpace;
+  }
+
+  bool operator==(const FilterPrimitiveDescription& aOther) const;
+  bool operator!=(const FilterPrimitiveDescription& aOther) const
+  {
+    return !(*this == aOther);
+  }
+
+private:
+  PrimitiveType mType;
+  AttributeMap mAttributes;
+  nsTArray<int32_t> mInputPrimitives;
+  IntRect mFilterPrimitiveSubregion;
+  IntRect mFilterSpaceBounds;
+  nsTArray<ColorSpace> mInputColorSpaces;
+  ColorSpace mOutputColorSpace;
+  bool mIsTainted;
+};
+
+/**
+ * A data structure that contains one or more FilterPrimitiveDescriptions.
+ * Designed to be serializable via IPDL, so it must not contain complex
+ * functionality.
+ */
+struct FilterDescription final {
+  FilterDescription() {}
+  explicit FilterDescription(const nsTArray<FilterPrimitiveDescription>& aPrimitives)
+   : mPrimitives(aPrimitives)
+  {}
+
+  bool operator==(const FilterDescription& aOther) const;
+  bool operator!=(const FilterDescription& aOther) const
+  {
+    return !(*this == aOther);
+  }
+
+  nsTArray<FilterPrimitiveDescription> mPrimitives;
+};
+
+/**
+ * The methods of this class are not on FilterDescription because
+ * FilterDescription is designed as a simple value holder that can be used
+ * on any thread.
+ */
+class FilterSupport {
+public:
+
+  /**
+   * Draw the filter described by aFilter. All rect parameters are in filter
+   * space coordinates. aRenderRect specifies the part of the filter output
+   * that will be drawn at (0, 0) into the draw target aDT, subject to the
+   * current transform on aDT but with no additional scaling.
+   * The source surfaces must match their corresponding rect in size.
+   * aAdditionalImages carries the images that are referenced by the
+   * eImageInputIndex attribute on any image primitives in the filter.
+   */
+  static void
+  RenderFilterDescription(DrawTarget* aDT,
+                          const FilterDescription& aFilter,
+                          const Rect& aRenderRect,
+                          SourceSurface* aSourceGraphic,
+                          const IntRect& aSourceGraphicRect,
+                          SourceSurface* aFillPaint,
+                          const IntRect& aFillPaintRect,
+                          SourceSurface* aStrokePaint,
+                          const IntRect& aStrokePaintRect,
+                          nsTArray<RefPtr<SourceSurface>>& aAdditionalImages,
+                          const Point& aDestPoint,
+                          const DrawOptions& aOptions = DrawOptions());
+
+  /**
+   * Computes the region that changes in the filter output due to a change in
+   * input.  This is primarily needed when an individual piece of content inside
+   * a filtered container element changes.
+   */
+  static nsIntRegion
+  ComputeResultChangeRegion(const FilterDescription& aFilter,
+                            const nsIntRegion& aSourceGraphicChange,
+                            const nsIntRegion& aFillPaintChange,
+                            const nsIntRegion& aStrokePaintChange);
+
+  /**
+   * Computes the regions that need to be supplied in the filter inputs when
+   * painting aResultNeededRegion of the filter output.
+   */
+  static void
+  ComputeSourceNeededRegions(const FilterDescription& aFilter,
+                             const nsIntRegion& aResultNeededRegion,
+                             nsIntRegion& aSourceGraphicNeededRegion,
+                             nsIntRegion& aFillPaintNeededRegion,
+                             nsIntRegion& aStrokePaintNeededRegion);
+
+  /**
+   * Computes the size of the filter output.
+   */
+  static nsIntRegion
+  ComputePostFilterExtents(const FilterDescription& aFilter,
+                           const nsIntRegion& aSourceGraphicExtents);
+
+  /**
+   * Computes the size of a single FilterPrimitiveDescription's output given a
+   * set of input extents.
+   */
+  static nsIntRegion
+  PostFilterExtentsForPrimitive(const FilterPrimitiveDescription& aDescription,
+                                const nsTArray<nsIntRegion>& aInputExtents);
+};
+
+} // namespace gfx
+} // namespace mozilla
+
+#endif // __FilterSupport_h
diff --git a/gfx/src/PingPongRegion.h b/gfx/src/PingPongRegion.h
new file mode 100644
index 000000000..d3bdcae1b
--- /dev/null
+++ b/gfx/src/PingPongRegion.h
@@ -0,0 +1,63 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef PingPongRegion_h__
+#define PingPongRegion_h__
+
+/* This class uses a pair of regions and swaps between them while
+ * accumulating to avoid the heap allocations associated with
+ * modifying a region in place.
+ *
+ * It is sizeof(T)*2 + sizeof(T*) and can use end up using
+ * approximately double the amount of memory as using single
+ * region so use it sparingly.
+ */
+
+template <typename T>
+class PingPongRegion
+{
+  typedef typename T::RectType RectType;
+public:
+  PingPongRegion()
+  {
+    rgn = &rgn1;
+  }
+
+  void SubOut(const RectType& aOther)
+  {
+    T* nextRgn = nextRegion();
+    nextRgn->Sub(*rgn, aOther);
+    rgn = nextRgn;
+  }
+
+  void OrWith(const RectType& aOther)
+  {
+    T* nextRgn = nextRegion();
+    nextRgn->Or(*rgn, aOther);
+    rgn = nextRgn;
+  }
+
+  T& Region()
+  {
+    return *rgn;
+  }
+
+private:
+
+  T* nextRegion()
+  {
+    if (rgn == &rgn1) {
+      return &rgn2;
+    } else {
+      return &rgn1;
+    }
+  }
+
+  T* rgn;
+  T rgn1;
+  T rgn2;
+};
+
+#endif
diff --git a/gfx/src/RegionBuilder.h b/gfx/src/RegionBuilder.h
new file mode 100644
index 000000000..c8bcd21b1
--- /dev/null
+++ b/gfx/src/RegionBuilder.h
@@ -0,0 +1,32 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ *  * License, v. 2.0. If a copy of the MPL was not distributed with this
+ *  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef RegionBuilder_h__
+#define RegionBuilder_h__
+
+#include <nsTArray.h>
+
+template <typename RegionType>
+class RegionBuilder
+{
+public:
+  typedef typename RegionType::RectType RectType;
+
+  RegionBuilder()
+  {}
+
+  void OrWith(const RectType& aRect) {
+    pixman_box32_t box = { aRect.x, aRect.y, aRect.XMost(), aRect.YMost() };
+    mRects.AppendElement(box);
+  }
+
+  RegionType ToRegion() const {
+    return RegionType(mRects);
+  }
+
+private:
+  nsTArray<pixman_box32_t> mRects;
+};
+
+#endif // RegionBuilder_h__
diff --git a/gfx/src/TiledRegion.cpp b/gfx/src/TiledRegion.cpp
new file mode 100644
index 000000000..efaa2346b
--- /dev/null
+++ b/gfx/src/TiledRegion.cpp
@@ -0,0 +1,370 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "TiledRegion.h"
+
+#include <algorithm>
+
+#include "mozilla/fallible.h"
+
+namespace mozilla {
+namespace gfx {
+
+static const int32_t kTileSize = 256;
+static const size_t kMaxTiles = 1000;
+
+/**
+ * TiledRegionImpl stores an array of non-empty rectangles (pixman_box32_ts) to
+ * represent the region. Each rectangle is contained in a single tile;
+ * rectangles never cross tile boundaries. The rectangles are sorted by their
+ * tile's origin in top-to-bottom, left-to-right order.
+ * (Note that this can mean that a rectangle r1 can come before another
+ * rectangle r2 even if r2.y1 < r1.y1, as long as the two rects are in the same
+ * row of tiles and r1.x1 < r2.x1.)
+ * Empty tiles take up no space in the array - there is no rectangle stored for
+ * them. As a result, any algorithm that needs to deal with empty tiles will
+ * iterate through the mRects array and compare the positions of two
+ * consecutive rects to figure out whether there are any empty tiles between
+ * them.
+ */
+
+static pixman_box32_t
+IntersectionOfNonEmptyBoxes(const pixman_box32_t& aBox1,
+                            const pixman_box32_t& aBox2)
+{
+  return pixman_box32_t {
+    std::max(aBox1.x1, aBox2.x1),
+    std::max(aBox1.y1, aBox2.y1),
+    std::min(aBox1.x2, aBox2.x2),
+    std::min(aBox1.y2, aBox2.y2)
+  };
+}
+
+// A TileIterator points to a specific tile inside a certain tile range, or to
+// the end of the tile range. Advancing a TileIterator will move to the next
+// tile inside the range (or to the range end). The next tile is either the
+// tile to the right of the current one, or the first tile of the next tile
+// row if the current tile is already the last tile in the row.
+class TileIterator {
+public:
+  TileIterator(const pixman_box32_t& aTileBounds, const IntPoint& aPosition)
+    : mTileBounds(aTileBounds)
+    , mPos(aPosition)
+  {}
+
+  bool operator!=(const TileIterator& aOther) { return mPos != aOther.mPos; }
+  bool operator==(const TileIterator& aOther) { return mPos == aOther.mPos; }
+
+  IntPoint operator*() const { return mPos; }
+
+  const TileIterator& operator++() {
+    mPos.x += kTileSize;
+    if (mPos.x >= mTileBounds.x2) {
+      mPos.x = mTileBounds.x1;
+      mPos.y += kTileSize;
+    }
+    return *this;
+  }
+
+  TileIterator& operator=(const IntPoint& aPosition)
+  {
+    mPos = aPosition;
+    return *this;
+  }
+
+  bool IsBeforeTileContainingPoint(const IntPoint& aPoint) const
+  {
+    return (mPos.y + kTileSize) <= aPoint.y  ||
+      (mPos.y <= aPoint.y && (mPos.x + kTileSize) <= aPoint.x);
+  }
+
+  bool IsAtTileContainingPoint(const IntPoint& aPoint) const
+  {
+    return mPos.y <= aPoint.y && aPoint.y < (mPos.y + kTileSize) &&
+           mPos.x <= aPoint.x && aPoint.x < (mPos.x + kTileSize);
+
+  }
+
+  pixman_box32_t IntersectionWith(const pixman_box32_t& aRect) const
+  {
+    pixman_box32_t tile = { mPos.x, mPos.y,
+                            mPos.x + kTileSize, mPos.y + kTileSize };
+    return IntersectionOfNonEmptyBoxes(tile, aRect);
+  }
+
+private:
+  const pixman_box32_t& mTileBounds;
+  IntPoint mPos;
+};
+
+// A TileRange describes a range of tiles contained inside a certain tile
+// bounds (which is a rectangle that includes all tiles that you're
+// interested in). The tile range can start and end at any point inside a
+// tile row.
+// The tile range end is described by the tile that starts at the bottom
+// left corner of the tile bounds, i.e. the first tile under the tile
+// bounds.
+class TileRange {
+public:
+  // aTileBounds, aStart and aEnd need to be aligned with the tile grid.
+  TileRange(const pixman_box32_t& aTileBounds,
+            const IntPoint& aStart, const IntPoint& aEnd)
+    : mTileBounds(aTileBounds)
+    , mStart(aStart)
+    , mEnd(aEnd)
+  {}
+  // aTileBounds needs to be aligned with the tile grid.
+  explicit TileRange(const pixman_box32_t& aTileBounds)
+    : mTileBounds(aTileBounds)
+    , mStart(mTileBounds.x1, mTileBounds.y1)
+    , mEnd(mTileBounds.x1, mTileBounds.y2)
+  {}
+
+  TileIterator Begin() const { return TileIterator(mTileBounds, mStart); }
+  TileIterator End() const { return TileIterator(mTileBounds, mEnd); }
+
+  // The number of tiles in this tile range.
+  size_t Length() const
+  {
+    if (mEnd.y == mStart.y) {
+      return (mEnd.x - mStart.x) / kTileSize;
+    }
+    int64_t numberOfFullRows = (((int64_t)mEnd.y - (int64_t)mStart.y) / kTileSize) - 1;
+    int64_t tilesInFirstRow = ((int64_t)mTileBounds.x2 - (int64_t)mStart.x) / kTileSize;
+    int64_t tilesInLastRow = ((int64_t)mEnd.x - (int64_t)mTileBounds.x1) / kTileSize;
+    int64_t tilesInFullRow = ((int64_t)mTileBounds.x2 - (int64_t)mTileBounds.x1) / kTileSize;
+    int64_t total = tilesInFirstRow + (tilesInFullRow * numberOfFullRows) + tilesInLastRow;
+    MOZ_ASSERT(total > 0);
+    // The total may be larger than what fits in a size_t, so clamp it to
+    // SIZE_MAX in that case.
+    return ((uint64_t)total > (uint64_t)SIZE_MAX) ? SIZE_MAX : (size_t)total;
+  }
+
+  // If aTileOrigin does not describe a tile inside our tile bounds, move it
+  // to the next tile that you'd encounter by "advancing" a tile iterator
+  // inside these tile bounds. If aTileOrigin is after the last tile inside
+  // our tile bounds, move it to the range end tile.
+  // The result of this method is a valid end tile for a tile range with our
+  // tile bounds.
+  IntPoint MoveIntoBounds(const IntPoint& aTileOrigin) const
+  {
+    IntPoint p = aTileOrigin;
+    if (p.x < mTileBounds.x1) {
+      p.x = mTileBounds.x1;
+    } else if (p.x >= mTileBounds.x2) {
+      p.x = mTileBounds.x1;
+      p.y += kTileSize;
+    }
+    if (p.y < mTileBounds.y1) {
+      p.y = mTileBounds.y1;
+      p.x = mTileBounds.x1;
+    } else if (p.y >= mTileBounds.y2) {
+      // There's only one valid state after the end of the tile range, and that's
+      // the bottom left point of the tile bounds.
+      p.x = mTileBounds.x1;
+      p.y = mTileBounds.y2;
+    }
+    return p;
+  }
+
+private:
+  const pixman_box32_t& mTileBounds;
+  const IntPoint mStart;
+  const IntPoint mEnd;
+};
+
+static IntPoint
+TileContainingPoint(const IntPoint& aPoint)
+{
+  return IntPoint(RoundDownToMultiple(aPoint.x, kTileSize),
+                  RoundDownToMultiple(aPoint.y, kTileSize));
+}
+
+enum class IterationAction : uint8_t {
+  CONTINUE,
+  STOP
+};
+
+enum class IterationEndReason : uint8_t {
+  NOT_STOPPED,
+  STOPPED
+};
+
+template<
+  typename HandleEmptyTilesFunction,
+  typename HandleNonEmptyTileFunction,
+  typename RectArrayT>
+IterationEndReason ProcessIntersectedTiles(const pixman_box32_t& aRect,
+                                           RectArrayT& aRectArray,
+                                           HandleEmptyTilesFunction aHandleEmptyTiles,
+                                           HandleNonEmptyTileFunction aHandleNonEmptyTile)
+{
+  pixman_box32_t tileBounds = {
+    RoundDownToMultiple(aRect.x1, kTileSize),
+    RoundDownToMultiple(aRect.y1, kTileSize),
+    RoundUpToMultiple(aRect.x2, kTileSize),
+    RoundUpToMultiple(aRect.y2, kTileSize)
+  };
+  if (tileBounds.x2 < tileBounds.x1 || tileBounds.y2 < tileBounds.y1) {
+    // RoundUpToMultiple probably overflowed. Bail out.
+    return IterationEndReason::STOPPED;
+  }
+
+  TileRange tileRange(tileBounds);
+  TileIterator rangeEnd = tileRange.End();
+
+  // tileIterator points to the next tile in tileRange, or to rangeEnd if we're
+  // done.
+  TileIterator tileIterator = tileRange.Begin();
+
+  // We iterate over the rectangle array. Depending on the position of the
+  // rectangle we encounter, we may need to advance tileIterator by zero, one,
+  // or more tiles:
+  //  - Zero if the rectangle we encountered is outside the tiles that
+  //    intersect aRect.
+  //  - One if the rectangle is in the exact tile that we're interested in next
+  //    (i.e. the tile that tileIterator points at).
+  //  - More than one if the encountered rectangle is in a tile that's further
+  //    to the right or to the bottom than tileIterator. In that case there is
+  //    at least one empty tile between the last rectangle we encountered and
+  //    the current one.
+  for (size_t i = 0; i < aRectArray.Length() && tileIterator != rangeEnd; i++) {
+    MOZ_ASSERT(aRectArray[i].x1 < aRectArray[i].x2 && aRectArray[i].y1 < aRectArray[i].y2, "empty rect");
+    IntPoint rectOrigin(aRectArray[i].x1, aRectArray[i].y1);
+    if (tileIterator.IsBeforeTileContainingPoint(rectOrigin)) {
+      IntPoint tileOrigin = TileContainingPoint(rectOrigin);
+      IntPoint afterEmptyTiles = tileRange.MoveIntoBounds(tileOrigin);
+      TileRange emptyTiles(tileBounds, *tileIterator, afterEmptyTiles);
+      if (aHandleEmptyTiles(aRectArray, i, emptyTiles) == IterationAction::STOP) {
+        return IterationEndReason::STOPPED;
+      }
+      tileIterator = afterEmptyTiles;
+      if (tileIterator == rangeEnd) {
+        return IterationEndReason::NOT_STOPPED;
+      }
+    }
+    if (tileIterator.IsAtTileContainingPoint(rectOrigin)) {
+      pixman_box32_t rectIntersection = tileIterator.IntersectionWith(aRect);
+      if (aHandleNonEmptyTile(aRectArray, i, rectIntersection) == IterationAction::STOP) {
+        return IterationEndReason::STOPPED;
+      }
+      ++tileIterator;
+    }
+  }
+
+  if (tileIterator != rangeEnd) {
+    // We've looked at all of our existing rectangles but haven't covered all
+    // of the tiles that we're interested in yet. So we need to deal with the
+    // remaining tiles now.
+    size_t endIndex = aRectArray.Length();
+    TileRange emptyTiles(tileBounds, *tileIterator, *rangeEnd);
+    if (aHandleEmptyTiles(aRectArray, endIndex, emptyTiles) == IterationAction::STOP) {
+      return IterationEndReason::STOPPED;
+    }
+  }
+  return IterationEndReason::NOT_STOPPED;
+}
+
+static pixman_box32_t
+UnionBoundsOfNonEmptyBoxes(const pixman_box32_t& aBox1,
+                           const pixman_box32_t& aBox2)
+{
+  return { std::min(aBox1.x1, aBox2.x1),
+           std::min(aBox1.y1, aBox2.y1),
+           std::max(aBox1.x2, aBox2.x2),
+           std::max(aBox1.y2, aBox2.y2) };
+}
+
+// Returns true when adding the rectangle was successful, and false if
+// allocation failed.
+// When this returns false, our internal state might not be consistent and we
+// need to be cleared.
+bool
+TiledRegionImpl::AddRect(const pixman_box32_t& aRect)
+{
+  // We are adding a rectangle that can span multiple tiles.
+  // For each empty tile that aRect intersects, we need to add the intersection
+  // of aRect with that tile to mRects, respecting the order of mRects.
+  // For each tile that already has a rectangle, we need to enlarge that
+  // existing rectangle to include the intersection of aRect with the tile.
+  return ProcessIntersectedTiles(aRect, mRects,
+    [&aRect](nsTArray<pixman_box32_t>& rects, size_t& rectIndex, TileRange emptyTiles) {
+      CheckedInt<size_t> newLength(rects.Length());
+      newLength += emptyTiles.Length();
+      if (!newLength.isValid() || newLength.value() >= kMaxTiles ||
+          !rects.InsertElementsAt(rectIndex, emptyTiles.Length(), fallible)) {
+        return IterationAction::STOP;
+      }
+      for (TileIterator tileIt = emptyTiles.Begin();
+           tileIt != emptyTiles.End();
+           ++tileIt, ++rectIndex) {
+        rects[rectIndex] = tileIt.IntersectionWith(aRect);
+      }
+      return IterationAction::CONTINUE;
+    },
+    [](nsTArray<pixman_box32_t>& rects, size_t rectIndex, const pixman_box32_t& rectIntersectionWithTile) {
+      rects[rectIndex] =
+        UnionBoundsOfNonEmptyBoxes(rects[rectIndex], rectIntersectionWithTile);
+      return IterationAction::CONTINUE;
+    }) == IterationEndReason::NOT_STOPPED;
+}
+
+static bool
+NonEmptyBoxesIntersect(const pixman_box32_t& aBox1, const pixman_box32_t& aBox2)
+{
+  return aBox1.x1 < aBox2.x2 && aBox2.x1 < aBox1.x2 &&
+         aBox1.y1 < aBox2.y2 && aBox2.y1 < aBox1.y2;
+}
+
+bool
+TiledRegionImpl::Intersects(const pixman_box32_t& aRect) const
+{
+  // aRect intersects this region if it intersects any of our rectangles.
+  return ProcessIntersectedTiles(aRect, mRects,
+    [](const nsTArray<pixman_box32_t>& rects, size_t& rectIndex, TileRange emptyTiles) {
+      // Ignore empty tiles and keep on iterating.
+      return IterationAction::CONTINUE;
+    },
+    [](const nsTArray<pixman_box32_t>& rects, size_t rectIndex, const pixman_box32_t& rectIntersectionWithTile) {
+      if (NonEmptyBoxesIntersect(rects[rectIndex], rectIntersectionWithTile)) {
+        // Found an intersecting rectangle, so aRect intersects this region.
+        return IterationAction::STOP;
+      }
+      return IterationAction::CONTINUE;
+    }) == IterationEndReason::STOPPED;
+}
+
+static bool
+NonEmptyBoxContainsNonEmptyBox(const pixman_box32_t& aBox1, const pixman_box32_t& aBox2)
+{
+  return aBox1.x1 <= aBox2.x1 && aBox2.x2 <= aBox1.x2 &&
+         aBox1.y1 <= aBox2.y1 && aBox2.y2 <= aBox1.y2;
+}
+
+bool
+TiledRegionImpl::Contains(const pixman_box32_t& aRect) const
+{
+  // aRect is contained in this region if aRect does not intersect any empty
+  // tiles and, for each non-empty tile, if the intersection of aRect with that
+  // tile is contained in the existing rectangle we have in that tile.
+  return ProcessIntersectedTiles(aRect, mRects,
+    [](const nsTArray<pixman_box32_t>& rects, size_t& rectIndex, TileRange emptyTiles) {
+      // Found an empty tile that intersects aRect, so aRect is not contained
+      // in this region.
+      return IterationAction::STOP;
+    },
+    [](const nsTArray<pixman_box32_t>& rects, size_t rectIndex, const pixman_box32_t& rectIntersectionWithTile) {
+      if (!NonEmptyBoxContainsNonEmptyBox(rects[rectIndex], rectIntersectionWithTile)) {
+        // Our existing rectangle in this tile does not cover the part of aRect that
+        // intersects this tile, so aRect is not contained in this region.
+        return IterationAction::STOP;
+      }
+      return IterationAction::CONTINUE;
+    }) == IterationEndReason::NOT_STOPPED;
+}
+
+} // namespace gfx
+} // namespace mozilla
diff --git a/gfx/src/TiledRegion.h b/gfx/src/TiledRegion.h
new file mode 100644
index 000000000..051773241
--- /dev/null
+++ b/gfx/src/TiledRegion.h
@@ -0,0 +1,208 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef MOZILLA_GFX_TILEDREGION_H_
+#define MOZILLA_GFX_TILEDREGION_H_
+
+#include "mozilla/ArrayView.h"
+#include "mozilla/gfx/Rect.h"
+#include "mozilla/Move.h"
+#include "nsRegion.h"
+#include "pixman.h"
+
+namespace mozilla {
+namespace gfx {
+
+// See TiledRegion.cpp for documentation on TiledRegionImpl.
+class TiledRegionImpl {
+public:
+  void Clear() { mRects.Clear(); }
+  bool AddRect(const pixman_box32_t& aRect);
+  bool Intersects(const pixman_box32_t& aRect) const;
+  bool Contains(const pixman_box32_t& aRect) const;
+  operator ArrayView<pixman_box32_t>() const { return ArrayView<pixman_box32_t>(mRects); }
+
+private:
+  nsTArray<pixman_box32_t> mRects;
+};
+
+/**
+ * A auto-simplifying region type that supports one rectangle per tile.
+ * The virtual tile grid is anchored at (0, 0) and has quadratic tiles whose
+ * size is hard-coded as kTileSize in TiledRegion.cpp.
+ * A TiledRegion starts out empty. You can add rectangles or (regular) regions
+ * into it by calling Add(). Add() is a mutating union operation (similar to
+ * OrWith on nsRegion) that's *not* exact, because it will enlarge the region as
+ * necessary to satisfy the "one rectangle per tile" requirement.
+ * Tiled regions convert implicitly to the underlying regular region type.
+ * The only way to remove parts from a TiledRegion is by calling SetEmpty().
+ */
+template<typename RegionT>
+class TiledRegion {
+public:
+  typedef typename RegionT::RectType RectT;
+
+  TiledRegion()
+    : mCoversBounds(false)
+  {}
+
+  TiledRegion(const TiledRegion& aOther)
+    : mBounds(aOther.mBounds)
+    , mImpl(aOther.mImpl)
+    , mCoversBounds(false)
+  {}
+
+  TiledRegion(TiledRegion&& aOther)
+    : mBounds(aOther.mBounds)
+    , mImpl(Move(aOther.mImpl))
+    , mCoversBounds(false)
+  {}
+
+  RegionT GetRegion() const
+  {
+    if (mBounds.IsEmpty()) {
+      return RegionT();
+    }
+    if (mCoversBounds) {
+      // Rect limit hit or allocation failed, treat as 1 rect.
+      return RegionT(mBounds);
+    }
+    return RegionT(mImpl);
+  }
+
+  TiledRegion& operator=(const TiledRegion& aOther)
+  {
+    if (&aOther != this) {
+      mBounds = aOther.mBounds;
+      mImpl = aOther.mImpl;
+      mCoversBounds = aOther.mCoversBounds;
+    }
+    return *this;
+  }
+
+  void Add(const RectT& aRect)
+  {
+    if (aRect.IsEmpty()) {
+      return;
+    }
+
+    Maybe<RectT> newBounds = mBounds.SafeUnion(aRect);
+    if (!newBounds) {
+      return;
+    }
+    mBounds = newBounds.value();
+    MOZ_ASSERT(!mBounds.Overflows());
+
+    if (mCoversBounds) {
+      return;
+    }
+
+    if (!mImpl.AddRect(RectToBox(aRect))) {
+      FallBackToBounds();
+    }
+  }
+
+  void Add(const RegionT& aRegion)
+  {
+    Maybe<RectT> newBounds = mBounds.SafeUnion(aRegion.GetBounds());
+    if (!newBounds) {
+      return;
+    }
+    mBounds = newBounds.value();
+    MOZ_ASSERT(!mBounds.Overflows());
+
+    if (mCoversBounds) {
+      return;
+    }
+
+    for (auto iter = aRegion.RectIter(); !iter.Done(); iter.Next()) {
+      RectT r = iter.Get();
+      if (r.IsEmpty() || r.Overflows()) {
+        // This can happen if e.g. a negative-width rect was wrapped into a
+        // region. Treat it the same as we would if such a rect was passed to
+        // the Add(const RectT&) function.
+        continue;
+      }
+      if (!mImpl.AddRect(RectToBox(r))) {
+        FallBackToBounds();
+        return;
+      }
+    }
+  }
+
+  bool IsEmpty() const { return mBounds.IsEmpty(); }
+
+  void SetEmpty()
+  {
+    mBounds.SetEmpty();
+    mImpl.Clear();
+    mCoversBounds = false;
+  }
+
+  RectT GetBounds() const { return mBounds; }
+  bool CoversBounds() const { return mCoversBounds; }
+
+  bool Intersects(const RectT& aRect) const
+  {
+    if (aRect.IsEmpty()) {
+      return true;
+    }
+    if (aRect.Overflows() || !mBounds.Intersects(aRect)) {
+      return false;
+    }
+    if (mCoversBounds) {
+      return true;
+    }
+
+    return mImpl.Intersects(RectToBox(aRect));
+  }
+
+  bool Contains(const RectT& aRect) const
+  {
+    if (aRect.IsEmpty()) {
+      return true;
+    }
+    if (aRect.Overflows() || !mBounds.Contains(aRect)) {
+      return false;
+    }
+    if (mCoversBounds) {
+      return true;
+    }
+    return mImpl.Contains(RectToBox(aRect));
+  }
+
+private:
+
+  void FallBackToBounds()
+  {
+    mCoversBounds = true;
+    mImpl.Clear();
+  }
+
+  static pixman_box32_t RectToBox(const RectT& aRect)
+  {
+    MOZ_ASSERT(!aRect.IsEmpty());
+    MOZ_ASSERT(!aRect.Overflows());
+    return { aRect.x, aRect.y, aRect.XMost(), aRect.YMost() };
+  }
+
+  RectT mBounds;
+  TiledRegionImpl mImpl;
+
+  // mCoversBounds is true if we bailed out due to a large number of tiles.
+  // mCoversBounds being true means that this TiledRegion is just a simple
+  // rectangle (our mBounds).
+  // Once set to true, the TiledRegion will stay in this state until SetEmpty
+  // is called.
+  bool mCoversBounds;
+};
+
+typedef TiledRegion<IntRegion> TiledIntRegion;
+
+} // namespace gfx
+} // namespace mozilla
+
+#endif /* MOZILLA_GFX_TILEDREGION_H_ */
diff --git a/gfx/src/X11UndefineNone.h b/gfx/src/X11UndefineNone.h
new file mode 100644
index 000000000..638bd0419
--- /dev/null
+++ b/gfx/src/X11UndefineNone.h
@@ -0,0 +1,23 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// The header <X11/X.h> defines "None" as a macro that expands to "0L".
+// This is terrible because many enumerations have an enumerator named "None".
+// To work around this, we undefine the macro "None", and define a replacement
+// macro named "X11None".
+// Include this header after including X11 headers, where necessary.
+#ifdef None
+#  undef None
+#  define X11None 0L
+// <X11/X.h> also defines "RevertToNone" as a macro that expands to "(int)None".
+// Since we are undefining "None", that stops working. To keep it working,
+// we undefine "RevertToNone" and redefine it in terms of "X11None".
+#  ifdef RevertToNone
+#    undef RevertToNone
+#    define RevertToNone (int)X11None
+#  endif
+#endif
+
diff --git a/gfx/src/X11Util.cpp b/gfx/src/X11Util.cpp
new file mode 100644
index 000000000..7dd02d2fd
--- /dev/null
+++ b/gfx/src/X11Util.cpp
@@ -0,0 +1,94 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: sw=2 ts=8 et :
+ */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "X11Util.h"
+#include "nsDebug.h"                    // for NS_ASSERTION, etc
+#include "MainThreadUtils.h"            // for NS_IsMainThread
+
+namespace mozilla {
+
+void
+FindVisualAndDepth(Display* aDisplay, VisualID aVisualID,
+                   Visual** aVisual, int* aDepth)
+{
+    const Screen* screen = DefaultScreenOfDisplay(aDisplay);
+
+    for (int d = 0; d < screen->ndepths; d++) {
+        Depth *d_info = &screen->depths[d];
+        for (int v = 0; v < d_info->nvisuals; v++) {
+            Visual* visual = &d_info->visuals[v];
+            if (visual->visualid == aVisualID) {
+                *aVisual = visual;
+                *aDepth = d_info->depth;
+                return;
+            }
+        }
+    }
+
+    NS_ASSERTION(aVisualID == X11None, "VisualID not on Screen.");
+    *aVisual = nullptr;
+    *aDepth = 0;
+    return;
+}
+
+void
+FinishX(Display* aDisplay)
+{
+  unsigned long lastRequest = NextRequest(aDisplay) - 1;
+  if (lastRequest == LastKnownRequestProcessed(aDisplay))
+    return;
+
+  XSync(aDisplay, False);
+}
+
+ScopedXErrorHandler::ErrorEvent* ScopedXErrorHandler::sXErrorPtr;
+
+int
+ScopedXErrorHandler::ErrorHandler(Display *, XErrorEvent *ev)
+{
+    // only record the error if no error was previously recorded.
+    // this means that in case of multiple errors, it's the first error that we report.
+    if (!sXErrorPtr->mError.error_code)
+      sXErrorPtr->mError = *ev;
+    return 0;
+}
+
+ScopedXErrorHandler::ScopedXErrorHandler(bool aAllowOffMainThread)
+{
+    if (!aAllowOffMainThread) {
+      // Off main thread usage is not safe in general, but OMTC GL layers uses this
+      // with the main thread blocked, which makes it safe.
+      NS_WARNING_ASSERTION(
+        NS_IsMainThread(),
+        "ScopedXErrorHandler being called off main thread, may cause issues");
+    }
+    // let sXErrorPtr point to this object's mXError object, but don't reset this mXError object!
+    // think of the case of nested ScopedXErrorHandler's.
+    mOldXErrorPtr = sXErrorPtr;
+    sXErrorPtr = &mXError;
+    mOldErrorHandler = XSetErrorHandler(ErrorHandler);
+}
+
+ScopedXErrorHandler::~ScopedXErrorHandler()
+{
+    sXErrorPtr = mOldXErrorPtr;
+    XSetErrorHandler(mOldErrorHandler);
+}
+
+bool
+ScopedXErrorHandler::SyncAndGetError(Display *dpy, XErrorEvent *ev)
+{
+    FinishX(dpy);
+
+    bool retval = mXError.mError.error_code != 0;
+    if (ev)
+        *ev = mXError.mError;
+    mXError = ErrorEvent(); // reset
+    return retval;
+}
+
+} // namespace mozilla
diff --git a/gfx/src/X11Util.h b/gfx/src/X11Util.h
new file mode 100644
index 000000000..e04913342
--- /dev/null
+++ b/gfx/src/X11Util.h
@@ -0,0 +1,148 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: sw=2 ts=8 et :
+ */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_X11Util_h
+#define mozilla_X11Util_h
+
+// Utilities common to all X clients, regardless of UI toolkit.
+
+#if defined(MOZ_WIDGET_GTK)
+#  include <gdk/gdk.h>
+#  include <gdk/gdkx.h>
+#  include "X11UndefineNone.h"
+#else
+#  error Unknown toolkit
+#endif
+
+#include <string.h>                     // for memset
+#include "mozilla/Scoped.h"             // for SCOPED_TEMPLATE
+
+namespace mozilla {
+
+/**
+ * Return the default X Display created and used by the UI toolkit.
+ */
+inline Display*
+DefaultXDisplay()
+{
+#if defined(MOZ_WIDGET_GTK)
+  return GDK_DISPLAY_XDISPLAY(gdk_display_get_default());
+#endif
+}
+
+/**
+ * Sets *aVisual to point to aDisplay's Visual struct corresponding to
+ * aVisualID, and *aDepth to its depth.  When aVisualID is None, these are set
+ * to nullptr and 0 respectively.  Both out-parameter pointers are assumed
+ * non-nullptr.
+ */
+void
+FindVisualAndDepth(Display* aDisplay, VisualID aVisualID,
+                   Visual** aVisual, int* aDepth);
+
+
+/**
+ * Ensure that all X requests have been processed.
+ *
+ * This is similar to XSync, but doesn't need a round trip if the previous
+ * request was synchronous or if events have been received since the last
+ * request.  Subsequent FinishX calls will be noops if there have been no
+ * intermediate requests.
+ */
+
+void
+FinishX(Display* aDisplay);
+
+/**
+ * Invoke XFree() on a pointer to memory allocated by Xlib (if the
+ * pointer is nonnull) when this class goes out of scope.
+ */
+template <typename T>
+struct ScopedXFreePtrTraits
+{
+  typedef T *type;
+  static T *empty() { return nullptr; }
+  static void release(T *ptr) { if (ptr != nullptr) XFree(ptr); }
+};
+SCOPED_TEMPLATE(ScopedXFree, ScopedXFreePtrTraits)
+
+/**
+ * On construction, set a graceful X error handler that doesn't crash the application and records X errors.
+ * On destruction, restore the X error handler to what it was before construction.
+ * 
+ * The SyncAndGetError() method allows to know whether a X error occurred, optionally allows to get the full XErrorEvent,
+ * and resets the recorded X error state so that a single X error will be reported only once.
+ *
+ * Nesting is correctly handled: multiple nested ScopedXErrorHandler's don't interfere with each other's state. However,
+ * if SyncAndGetError is not called on the nested ScopedXErrorHandler, then any X errors caused by X calls made while the nested
+ * ScopedXErrorHandler was in place may then be caught by the other ScopedXErrorHandler. This is just a result of X being
+ * asynchronous and us not doing any implicit syncing: the only method in this class what causes syncing is SyncAndGetError().
+ *
+ * This class is not thread-safe at all. It is assumed that only one thread is using any ScopedXErrorHandler's. Given that it's
+ * not used on Mac, it should be easy to make it thread-safe by using thread-local storage with __thread.
+ */
+class ScopedXErrorHandler
+{
+public:
+    // trivial wrapper around XErrorEvent, just adding ctor initializing by zero.
+    struct ErrorEvent
+    {
+        XErrorEvent mError;
+
+        ErrorEvent()
+        {
+            memset(this, 0, sizeof(ErrorEvent));
+        }
+    };
+
+private:
+
+    // this ScopedXErrorHandler's ErrorEvent object
+    ErrorEvent mXError;
+
+    // static pointer for use by the error handler
+    static ErrorEvent* sXErrorPtr;
+
+    // what to restore sXErrorPtr to on destruction
+    ErrorEvent* mOldXErrorPtr;
+
+    // what to restore the error handler to on destruction
+    int (*mOldErrorHandler)(Display *, XErrorEvent *);
+
+public:
+
+    static int
+    ErrorHandler(Display *, XErrorEvent *ev);
+
+    /**
+     * @param aAllowOffMainThread whether to warn if used off main thread
+     */
+    explicit ScopedXErrorHandler(bool aAllowOffMainThread = false);
+
+    ~ScopedXErrorHandler();
+
+    /** \returns true if a X error occurred since the last time this method was called on this ScopedXErrorHandler object,
+     *           or since the creation of this ScopedXErrorHandler object if this method was never called on it.
+     *
+     * \param ev this optional parameter, if set, will be filled with the XErrorEvent object. If multiple errors occurred,
+     *           the first one will be returned.
+     */
+    bool SyncAndGetError(Display *dpy, XErrorEvent *ev = nullptr);
+};
+
+class OffMainThreadScopedXErrorHandler : public ScopedXErrorHandler
+{
+public:
+  OffMainThreadScopedXErrorHandler()
+    : ScopedXErrorHandler(true)
+  {
+  }
+};
+
+} // namespace mozilla
+
+#endif  // mozilla_X11Util_h
diff --git a/gfx/src/gfxCrashReporterUtils.cpp b/gfx/src/gfxCrashReporterUtils.cpp
new file mode 100644
index 000000000..42647ccc6
--- /dev/null
+++ b/gfx/src/gfxCrashReporterUtils.cpp
@@ -0,0 +1,145 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "gfxCrashReporterUtils.h"
+
+#if defined(MOZ_CRASHREPORTER)
+#define MOZ_GFXFEATUREREPORTER 1
+#endif
+
+#ifdef MOZ_GFXFEATUREREPORTER
+#include "gfxCrashReporterUtils.h"
+#include <string.h>                     // for strcmp
+#include "mozilla/Assertions.h"         // for MOZ_ASSERT_HELPER2
+#include "mozilla/Services.h"           // for GetObserverService
+#include "mozilla/StaticMutex.h"
+#include "mozilla/mozalloc.h"           // for operator new, etc
+#include "mozilla/RefPtr.h"             // for RefPtr
+#include "nsCOMPtr.h"                   // for nsCOMPtr
+#include "nsError.h"                    // for NS_OK, NS_FAILED, nsresult
+#include "nsExceptionHandler.h"         // for AppendAppNotesToCrashReport
+#include "nsID.h"
+#include "nsIEventTarget.h"             // for NS_DISPATCH_NORMAL
+#include "nsIObserver.h"                // for nsIObserver, etc
+#include "nsIObserverService.h"         // for nsIObserverService
+#include "nsIRunnable.h"                // for nsIRunnable
+#include "nsISupports.h"
+#include "nsTArray.h"                   // for nsTArray
+#include "nsThreadUtils.h"              // for NS_DispatchToMainThread, etc
+#include "nscore.h"                     // for NS_IMETHOD, NS_IMETHODIMP, etc
+
+namespace mozilla {
+
+static nsTArray<nsCString> *gFeaturesAlreadyReported = nullptr;
+static StaticMutex gFeaturesAlreadyReportedMutex;
+
+class ObserverToDestroyFeaturesAlreadyReported final : public nsIObserver
+{
+
+public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIOBSERVER
+
+  ObserverToDestroyFeaturesAlreadyReported() {}
+private:
+  virtual ~ObserverToDestroyFeaturesAlreadyReported() {}
+};
+
+NS_IMPL_ISUPPORTS(ObserverToDestroyFeaturesAlreadyReported,
+                  nsIObserver)
+
+NS_IMETHODIMP
+ObserverToDestroyFeaturesAlreadyReported::Observe(nsISupports* aSubject,
+                                                  const char* aTopic,
+                                                  const char16_t* aData)
+{
+  if (!strcmp(aTopic, "xpcom-shutdown")) {
+    StaticMutexAutoLock al(gFeaturesAlreadyReportedMutex);
+    if (gFeaturesAlreadyReported) {
+      delete gFeaturesAlreadyReported;
+      gFeaturesAlreadyReported = nullptr;
+    }
+  }
+  return NS_OK;
+}
+
+class RegisterObserverRunnable : public Runnable {
+public:
+  NS_IMETHOD Run() override {
+    // LeakLog made me do this. Basically, I just wanted gFeaturesAlreadyReported to be a static nsTArray<nsCString>,
+    // and LeakLog was complaining about leaks like this:
+    //    leaked 1 instance of nsTArray_base with size 8 bytes
+    //    leaked 7 instances of nsStringBuffer with size 8 bytes each (56 bytes total)
+    // So this is a work-around using a pointer, and using a nsIObserver to deallocate on xpcom shutdown.
+    // Yay for fighting bloat.
+    nsCOMPtr<nsIObserverService> observerService = mozilla::services::GetObserverService();
+    if (!observerService)
+      return NS_OK;
+    RefPtr<ObserverToDestroyFeaturesAlreadyReported> observer = new ObserverToDestroyFeaturesAlreadyReported;
+    observerService->AddObserver(observer, "xpcom-shutdown", false);
+    return NS_OK;
+  }
+};
+
+class AppendAppNotesRunnable : public CancelableRunnable {
+public:
+  explicit AppendAppNotesRunnable(const nsACString& aFeatureStr)
+    : mFeatureString(aFeatureStr)
+  {
+  }
+
+  NS_IMETHOD Run() override {
+    CrashReporter::AppendAppNotesToCrashReport(mFeatureString);
+    return NS_OK;
+  }
+
+private:
+  nsAutoCString mFeatureString;
+};
+
+void
+ScopedGfxFeatureReporter::WriteAppNote(char statusChar)
+{
+  StaticMutexAutoLock al(gFeaturesAlreadyReportedMutex);
+
+  if (!gFeaturesAlreadyReported) {
+    gFeaturesAlreadyReported = new nsTArray<nsCString>;
+    nsCOMPtr<nsIRunnable> r = new RegisterObserverRunnable();
+    NS_DispatchToMainThread(r);
+  }
+
+  nsAutoCString featureString;
+  featureString.AppendPrintf("%s%c ",
+                             mFeature,
+                             statusChar);
+
+  if (!gFeaturesAlreadyReported->Contains(featureString)) {
+    gFeaturesAlreadyReported->AppendElement(featureString);
+    AppNote(featureString);
+  }
+}
+
+void
+ScopedGfxFeatureReporter::AppNote(const nsACString& aMessage)
+{
+  if (NS_IsMainThread()) {
+    CrashReporter::AppendAppNotesToCrashReport(aMessage);
+  } else {
+    nsCOMPtr<nsIRunnable> r = new AppendAppNotesRunnable(aMessage);
+    NS_DispatchToMainThread(r);
+  }
+}
+  
+} // end namespace mozilla
+
+#else
+
+namespace mozilla {
+void ScopedGfxFeatureReporter::WriteAppNote(char) {}
+void ScopedGfxFeatureReporter::AppNote(const nsACString&) {}
+  
+} // namespace mozilla
+
+#endif
diff --git a/gfx/src/gfxCrashReporterUtils.h b/gfx/src/gfxCrashReporterUtils.h
new file mode 100644
index 000000000..efc5ab1ab
--- /dev/null
+++ b/gfx/src/gfxCrashReporterUtils.h
@@ -0,0 +1,51 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef gfxCrashReporterUtils_h__
+#define gfxCrashReporterUtils_h__
+
+#include "nsString.h"
+
+namespace mozilla {
+
+/** \class ScopedGfxFeatureReporter
+  *
+  * On creation, adds "FeatureName?" to AppNotes
+  * On destruction, adds "FeatureName-", or "FeatureName+" if you called SetSuccessful().
+  *
+  * Any such string is added at most once to AppNotes, and is subsequently skipped.
+  *
+  * This ScopedGfxFeatureReporter class is designed to be fool-proof to use in functions that
+  * have many exit points. We don't want to encourage having function with many exit points.
+  * It just happens that our graphics features initialization functions are like that.
+  */
+class ScopedGfxFeatureReporter
+{
+public:
+  explicit ScopedGfxFeatureReporter(const char *aFeature, bool aForce = false)
+    : mFeature(aFeature), mStatusChar('-')
+  {
+    WriteAppNote(aForce ? '!' : '?');
+  }
+  ~ScopedGfxFeatureReporter() {
+    WriteAppNote(mStatusChar);
+  }
+  void SetSuccessful() { mStatusChar = '+'; }
+
+  static void AppNote(const nsACString& aMessage);
+
+  class AppNoteWritingRunnable;
+
+protected:
+  const char *mFeature;
+  char mStatusChar;
+
+private:
+  void WriteAppNote(char statusChar);
+};
+
+} // end namespace mozilla
+
+#endif // gfxCrashReporterUtils_h__
diff --git a/gfx/src/gfxTelemetry.cpp b/gfx/src/gfxTelemetry.cpp
new file mode 100644
index 000000000..9ea15dcbd
--- /dev/null
+++ b/gfx/src/gfxTelemetry.cpp
@@ -0,0 +1,59 @@
+/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#include "gfxTelemetry.h"
+
+namespace mozilla {
+namespace gfx {
+
+const char*
+FeatureStatusToString(FeatureStatus aStatus)
+{
+  switch (aStatus) {
+    case FeatureStatus::Unused:
+      return "unused";
+    case FeatureStatus::Unavailable:
+      return "unavailable";
+    case FeatureStatus::CrashedInHandler:
+      return "crashed";
+    case FeatureStatus::Blocked:
+      return "blocked";
+    case FeatureStatus::Blacklisted:
+      return "blacklisted";
+    case FeatureStatus::Failed:
+      return "failed";
+    case FeatureStatus::Disabled:
+      return "disabled";
+    case FeatureStatus::Available:
+      return "available";
+    case FeatureStatus::ForceEnabled:
+      return "force_enabled";
+    case FeatureStatus::CrashedOnStartup:
+      return "crashed_on_startup";
+    case FeatureStatus::Broken:
+      return "broken";
+    default:
+      MOZ_ASSERT_UNREACHABLE("missing status case");
+      return "unknown";
+  }
+}
+
+bool
+IsFeatureStatusFailure(FeatureStatus aStatus)
+{
+  return !(aStatus == FeatureStatus::Unused ||
+           aStatus == FeatureStatus::Available ||
+           aStatus == FeatureStatus::ForceEnabled);
+}
+
+bool
+IsFeatureStatusSuccess(FeatureStatus aStatus)
+{
+  return aStatus == FeatureStatus::Available ||
+         aStatus == FeatureStatus::ForceEnabled;
+}
+
+} // namespace gfx
+} // namespace mozilla
diff --git a/gfx/src/gfxTelemetry.h b/gfx/src/gfxTelemetry.h
new file mode 100644
index 000000000..9f0f618f0
--- /dev/null
+++ b/gfx/src/gfxTelemetry.h
@@ -0,0 +1,70 @@
+/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#ifndef gfx_src_gfxTelemetry_h__
+#define gfx_src_gfxTelemetry_h__
+
+namespace mozilla {
+namespace gfx {
+
+// Describes the status of a graphics feature, in terms of whether or not we've
+// attempted to initialize the feature, and if so, whether or not it succeeded
+// (and if not, why).
+enum class FeatureStatus
+{
+  // This feature has not been requested.
+  Unused,
+
+  // This feature is unavailable due to Safe Mode, not being included with
+  // the operating system, or a dependent feature being disabled.
+  Unavailable,
+
+  // This feature crashed immediately when we tried to initialize it, but we
+  // were able to recover via SEH (or something similar).
+  CrashedInHandler,
+
+  // This feature was blocked for reasons outside the blacklist, such as a
+  // runtime test failing.
+  Blocked,
+
+  // This feature has been blocked by the graphics blacklist.
+  Blacklisted,
+
+  // This feature was attempted but failed to activate.
+  Failed,
+
+  // This feature was explicitly disabled by the user.
+  Disabled,
+
+  // This feature is available for use.
+  Available,
+
+  // This feature was explicitly force-enabled by the user.
+  ForceEnabled,
+
+  // This feature was disabled due to the startup crash guard.
+  CrashedOnStartup,
+
+  // This feature was attempted but later determined to be broken.
+  Broken,
+
+  // Add new entries above here.
+  LAST
+};
+
+const char* FeatureStatusToString(FeatureStatus aStatus);
+bool IsFeatureStatusFailure(FeatureStatus aStatus);
+bool IsFeatureStatusSuccess(FeatureStatus aStatus);
+
+enum class TelemetryDeviceCode : uint32_t {
+  Content = 0,
+  Image = 1,
+  D2D1 = 2
+};
+
+} // namespace gfx
+} // namespace mozilla
+
+#endif // gfx_src_gfxTelemetry_h__
diff --git a/gfx/src/moz.build b/gfx/src/moz.build
new file mode 100644
index 000000000..3678eee7a
--- /dev/null
+++ b/gfx/src/moz.build
@@ -0,0 +1,94 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+XPIDL_SOURCES += [
+    'nsIFontEnumerator.idl',
+    'nsIScriptableRegion.idl',
+]
+
+XPIDL_MODULE = 'gfx'
+
+DEFINES['MOZ_APP_VERSION'] = '"%s"' % CONFIG['MOZ_APP_VERSION']
+
+EXPORTS += [
+    'DriverCrashGuard.h',
+    'FilterSupport.h',
+    'gfxCrashReporterUtils.h',
+    'gfxTelemetry.h',
+    'nsBoundingMetrics.h',
+    'nsColor.h',
+    'nsColorNameList.h',
+    'nsColorNames.h',
+    'nsCoord.h',
+    'nsDeviceContext.h',
+    'nsFont.h',
+    'nsFontMetrics.h',
+    'nsGfxCIID.h',
+    'nsITheme.h',
+    'nsMargin.h',
+    'nsPoint.h',
+    'nsRect.h',
+    'nsRegion.h',
+    'nsRegionFwd.h',
+    'nsRenderingContext.h',
+    'nsSize.h',
+    'nsThemeConstants.h',
+    'nsTransform2D.h',
+    'PingPongRegion.h',
+    'RegionBuilder.h',
+    'X11UndefineNone.h'
+]
+
+EXPORTS.mozilla += [
+    'AppUnits.h',
+    'ArrayView.h',
+]
+
+EXPORTS.mozilla.gfx += [
+    'TiledRegion.h',
+]
+
+if CONFIG['MOZ_X11']:
+    EXPORTS.mozilla += ['X11Util.h']
+    SOURCES += [
+        'X11Util.cpp',
+    ]
+
+UNIFIED_SOURCES += [
+    'DriverCrashGuard.cpp',
+    'FilterSupport.cpp',
+    'gfxCrashReporterUtils.cpp',
+    'gfxTelemetry.cpp',
+    'nsColor.cpp',
+    'nsFont.cpp',
+    'nsFontMetrics.cpp',
+    'nsRect.cpp',
+    'nsRegion.cpp',
+    'nsScriptableRegion.cpp',
+    'nsThebesFontEnumerator.cpp',
+    'nsThebesGfxFactory.cpp',
+    'nsTransform2D.cpp',
+    'TiledRegion.cpp',
+]
+
+# nsDeviceContext.cpp cannot be built in unified mode because it pulls in OS X system headers.
+SOURCES += [
+    'nsDeviceContext.cpp',
+]
+
+include('/ipc/chromium/chromium-config.mozbuild')
+
+LOCAL_INCLUDES += [
+    '/dom/ipc',  # for ContentChild.h
+]
+
+FINAL_LIBRARY = 'xul'
+
+CXXFLAGS += CONFIG['MOZ_CAIRO_CFLAGS']
+CXXFLAGS += CONFIG['TK_CFLAGS']
+
+if 'gtk' in CONFIG['MOZ_WIDGET_TOOLKIT']:
+    CXXFLAGS += CONFIG['MOZ_PANGO_CFLAGS']
diff --git a/gfx/src/nsBoundingMetrics.h b/gfx/src/nsBoundingMetrics.h
new file mode 100644
index 000000000..4665db24f
--- /dev/null
+++ b/gfx/src/nsBoundingMetrics.h
@@ -0,0 +1,87 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef __nsBoundingMetrics_h
+#define __nsBoundingMetrics_h
+
+#include "nsCoord.h"
+#include <algorithm>
+
+/* Struct used for accurate measurements of a string, in order to
+ * allow precise positioning when processing MathML.  This is in its
+ * own header file because some very-widely-included headers need it
+ * but not the rest of nsFontMetrics, or vice versa.
+ */
+
+struct nsBoundingMetrics {
+
+    ///////////
+    // Metrics that _exactly_ enclose the text:
+
+    // The character coordinate system is the one used on X Windows:
+    // 1. The origin is located at the intersection of the baseline
+    //    with the left of the character's cell.
+    // 2. All horizontal bearings are oriented from left to right.
+    // 2. All horizontal bearings are oriented from left to right.
+    // 3. The ascent is oriented from bottom to top (being 0 at the orgin).
+    // 4. The descent is oriented from top to bottom (being 0 at the origin).
+
+    // Note that Win32/Mac/PostScript use a different convention for
+    // the descent (all vertical measurements are oriented from bottom
+    // to top on these palatforms). Make sure to flip the sign of the
+    // descent on these platforms for cross-platform compatibility.
+
+    // Any of the following member variables listed here can have
+    // positive or negative value.
+
+    nscoord leftBearing;
+    /* The horizontal distance from the origin of the drawing
+       operation to the left-most part of the drawn string. */
+
+    nscoord rightBearing;
+    /* The horizontal distance from the origin of the drawing
+       operation to the right-most part of the drawn string.
+       The _exact_ width of the string is therefore:
+       rightBearing - leftBearing */
+
+    nscoord ascent;
+    /* The vertical distance from the origin of the drawing
+       operation to the top-most part of the drawn string. */
+
+    nscoord descent;
+    /* The vertical distance from the origin of the drawing
+       operation to the bottom-most part of the drawn string.
+       The _exact_ height of the string is therefore:
+       ascent + descent */
+
+    nscoord width;
+    /* The horizontal distance from the origin of the drawing
+       operation to the correct origin for drawing another string
+       to follow the current one. Depending on the font, this
+       could be greater than or less than the right bearing. */
+
+    nsBoundingMetrics() : leftBearing(0), rightBearing(0),
+                          ascent(0), descent(0), width(0)
+    {}
+
+    void
+    operator += (const nsBoundingMetrics& bm) {
+        if (ascent + descent == 0 && rightBearing - leftBearing == 0) {
+            ascent = bm.ascent;
+            descent = bm.descent;
+            leftBearing = width + bm.leftBearing;
+            rightBearing = width + bm.rightBearing;
+        }
+        else {
+            if (ascent < bm.ascent) ascent = bm.ascent;
+            if (descent < bm.descent) descent = bm.descent;
+            leftBearing = std::min(leftBearing, width + bm.leftBearing);
+            rightBearing = std::max(rightBearing, width + bm.rightBearing);
+        }
+        width += bm.width;
+    }
+};
+
+#endif // __nsBoundingMetrics_h
diff --git a/gfx/src/nsColor.cpp b/gfx/src/nsColor.cpp
new file mode 100644
index 000000000..359f9fde4
--- /dev/null
+++ b/gfx/src/nsColor.cpp
@@ -0,0 +1,361 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/ArrayUtils.h"         // for ArrayLength
+#include "mozilla/mozalloc.h"           // for operator delete, etc
+#include "mozilla/MathAlgorithms.h"
+
+#include "nsColor.h"
+#include <sys/types.h>                  // for int32_t
+#include "nsColorNames.h"               // for nsColorNames
+#include "nsDebug.h"                    // for NS_ASSERTION, etc
+#include "nsStaticNameTable.h"
+#include "nsString.h"                   // for nsAutoCString, nsString, etc
+#include "nscore.h"                     // for nsAString, etc
+
+using namespace mozilla;
+
+// define an array of all color names
+#define GFX_COLOR(_name, _value) #_name,
+static const char* const kColorNames[] = {
+#include "nsColorNameList.h"
+};
+#undef GFX_COLOR
+
+// define an array of all color name values
+#define GFX_COLOR(_name, _value) _value,
+static const nscolor kColors[] = {
+#include "nsColorNameList.h"
+};
+#undef GFX_COLOR
+
+#define eColorName_COUNT (ArrayLength(kColorNames))
+#define eColorName_UNKNOWN (-1)
+
+static nsStaticCaseInsensitiveNameTable* gColorTable = nullptr;
+
+void nsColorNames::AddRefTable(void) 
+{
+  NS_ASSERTION(!gColorTable, "pre existing array!");
+  if (!gColorTable) {
+    gColorTable =
+      new nsStaticCaseInsensitiveNameTable(kColorNames, eColorName_COUNT);
+  }
+}
+
+void nsColorNames::ReleaseTable(void)
+{
+  if (gColorTable) {
+    delete gColorTable;
+    gColorTable = nullptr;
+  }
+}
+
+static int ComponentValue(const char16_t* aColorSpec, int aLen, int color, int dpc)
+{
+  int component = 0;
+  int index = (color * dpc);
+  if (2 < dpc) {
+    dpc = 2;
+  }
+  while (--dpc >= 0) {
+    char16_t ch = ((index < aLen) ? aColorSpec[index++] : '0');
+    if (('0' <= ch) && (ch <= '9')) {
+      component = (component * 16) + (ch - '0');
+    } else if ((('a' <= ch) && (ch <= 'f')) || 
+               (('A' <= ch) && (ch <= 'F'))) {
+      // "ch&7" handles lower and uppercase hex alphabetics
+      component = (component * 16) + (ch & 7) + 9;
+    }
+    else {  // not a hex digit, treat it like 0
+      component = (component * 16);
+    }
+  }
+  return component;
+}
+
+bool
+NS_HexToRGBA(const nsAString& aColorSpec, nsHexColorType aType,
+             nscolor* aResult)
+{
+  const char16_t* buffer = aColorSpec.BeginReading();
+
+  int nameLen = aColorSpec.Length();
+  bool hasAlpha = false;
+  if (nameLen != 3 && nameLen != 6) {
+    if ((nameLen != 4 && nameLen != 8) || aType == nsHexColorType::NoAlpha) {
+      // Improperly formatted color value
+      return false;
+    }
+    hasAlpha = true;
+  }
+
+  // Make sure the digits are legal
+  for (int i = 0; i < nameLen; i++) {
+    char16_t ch = buffer[i];
+    if (((ch >= '0') && (ch <= '9')) ||
+        ((ch >= 'a') && (ch <= 'f')) ||
+        ((ch >= 'A') && (ch <= 'F'))) {
+      // Legal character
+      continue;
+    }
+    // Whoops. Illegal character.
+    return false;
+  }
+
+  // Convert the ascii to binary
+  int dpc = ((nameLen <= 4) ? 1 : 2);
+  // Translate components from hex to binary
+  int r = ComponentValue(buffer, nameLen, 0, dpc);
+  int g = ComponentValue(buffer, nameLen, 1, dpc);
+  int b = ComponentValue(buffer, nameLen, 2, dpc);
+  int a;
+  if (hasAlpha) {
+    a = ComponentValue(buffer, nameLen, 3, dpc);
+  } else {
+    a = (dpc == 1) ? 0xf : 0xff;
+  }
+  if (dpc == 1) {
+    // Scale single digit component to an 8 bit value. Replicate the
+    // single digit to compute the new value.
+    r = (r << 4) | r;
+    g = (g << 4) | g;
+    b = (b << 4) | b;
+    a = (a << 4) | a;
+  }
+  NS_ASSERTION((r >= 0) && (r <= 255), "bad r");
+  NS_ASSERTION((g >= 0) && (g <= 255), "bad g");
+  NS_ASSERTION((b >= 0) && (b <= 255), "bad b");
+  NS_ASSERTION((a >= 0) && (a <= 255), "bad a");
+  *aResult = NS_RGBA(r, g, b, a);
+  return true;
+}
+
+// This implements part of the algorithm for legacy behavior described in
+// http://www.whatwg.org/specs/web-apps/current-work/complete/common-microsyntaxes.html#rules-for-parsing-a-legacy-color-value
+bool NS_LooseHexToRGB(const nsString& aColorSpec, nscolor* aResult)
+{
+  if (aColorSpec.EqualsLiteral("transparent")) {
+    return false;
+  }
+
+  int nameLen = aColorSpec.Length();
+  const char16_t* colorSpec = aColorSpec.get();
+  if (nameLen > 128) {
+    nameLen = 128;
+  }
+
+  if ('#' == colorSpec[0]) {
+    ++colorSpec;
+    --nameLen;
+  }
+
+  // digits per component
+  int dpc = (nameLen + 2) / 3;
+  int newdpc = dpc;
+
+  // Use only the rightmost 8 characters of each component.
+  if (newdpc > 8) {
+    nameLen -= newdpc - 8;
+    colorSpec += newdpc - 8;
+    newdpc = 8;
+  }
+
+  // And then keep trimming characters at the left until we'd trim one
+  // that would leave a nonzero value, but not past 2 characters per
+  // component.
+  while (newdpc > 2) {
+    bool haveNonzero = false;
+    for (int c = 0; c < 3; ++c) {
+      MOZ_ASSERT(c * dpc < nameLen,
+                 "should not pass end of string while newdpc > 2");
+      char16_t ch = colorSpec[c * dpc];
+      if (('1' <= ch && ch <= '9') ||
+          ('A' <= ch && ch <= 'F') ||
+          ('a' <= ch && ch <= 'f')) {
+        haveNonzero = true;
+        break;
+      }
+    }
+    if (haveNonzero) {
+      break;
+    }
+    --newdpc;
+    --nameLen;
+    ++colorSpec;
+  }
+
+  // Translate components from hex to binary
+  int r = ComponentValue(colorSpec, nameLen, 0, dpc);
+  int g = ComponentValue(colorSpec, nameLen, 1, dpc);
+  int b = ComponentValue(colorSpec, nameLen, 2, dpc);
+  NS_ASSERTION((r >= 0) && (r <= 255), "bad r");
+  NS_ASSERTION((g >= 0) && (g <= 255), "bad g");
+  NS_ASSERTION((b >= 0) && (b <= 255), "bad b");
+
+  *aResult = NS_RGB(r, g, b);
+  return true;
+}
+
+bool NS_ColorNameToRGB(const nsAString& aColorName, nscolor* aResult)
+{
+  if (!gColorTable) return false;
+
+  int32_t id = gColorTable->Lookup(aColorName);
+  if (eColorName_UNKNOWN < id) {
+    NS_ASSERTION(uint32_t(id) < eColorName_COUNT,
+                 "gColorTable->Lookup messed up");
+    if (aResult) {
+      *aResult = kColors[id];
+    }
+    return true;
+  }
+  return false;
+}
+
+// Returns kColorNames, an array of all possible color names, and sets
+// *aSizeArray to the size of that array. Do NOT call free() on this array.
+const char * const * NS_AllColorNames(size_t *aSizeArray)
+{
+  *aSizeArray = ArrayLength(kColorNames);
+  return kColorNames;
+}
+
+// Macro to blend two colors
+//
+// equivalent to target = (bg*(255-fgalpha) + fg*fgalpha)/255
+#define MOZ_BLEND(target, bg, fg, fgalpha)       \
+  FAST_DIVIDE_BY_255(target, (bg)*(255-fgalpha) + (fg)*(fgalpha))
+
+nscolor
+NS_ComposeColors(nscolor aBG, nscolor aFG)
+{
+  // This function uses colors that are non premultiplied alpha.
+  int r, g, b, a;
+
+  int bgAlpha = NS_GET_A(aBG);
+  int fgAlpha = NS_GET_A(aFG);
+
+  // Compute the final alpha of the blended color
+  // a = fgAlpha + bgAlpha*(255 - fgAlpha)/255;
+  FAST_DIVIDE_BY_255(a, bgAlpha*(255-fgAlpha));
+  a = fgAlpha + a;
+  int blendAlpha;
+  if (a == 0) {
+    // In this case the blended color is totally trasparent,
+    // we preserve the color information of the foreground color.
+    blendAlpha = 255;
+  } else {
+    blendAlpha = (fgAlpha*255)/a;
+  }
+  MOZ_BLEND(r, NS_GET_R(aBG), NS_GET_R(aFG), blendAlpha);
+  MOZ_BLEND(g, NS_GET_G(aBG), NS_GET_G(aFG), blendAlpha);
+  MOZ_BLEND(b, NS_GET_B(aBG), NS_GET_B(aFG), blendAlpha);
+
+  return NS_RGBA(r, g, b, a);
+}
+
+namespace mozilla {
+
+static uint32_t
+BlendColorComponent(uint32_t aBg, uint32_t aFg, uint32_t aFgAlpha)
+{
+  return RoundingDivideBy255(aBg * (255 - aFgAlpha) + aFg * aFgAlpha);
+}
+
+nscolor
+LinearBlendColors(nscolor aBg, nscolor aFg, uint_fast8_t aFgRatio)
+{
+  // Common case that either pure background or pure foreground
+  if (aFgRatio == 0) {
+    return aBg;
+  }
+  if (aFgRatio == 255) {
+    return aFg;
+  }
+  // Common case that alpha channel is equal (usually both are opaque)
+  if (NS_GET_A(aBg) == NS_GET_A(aFg)) {
+    auto r = BlendColorComponent(NS_GET_R(aBg), NS_GET_R(aFg), aFgRatio);
+    auto g = BlendColorComponent(NS_GET_G(aBg), NS_GET_G(aFg), aFgRatio);
+    auto b = BlendColorComponent(NS_GET_B(aBg), NS_GET_B(aFg), aFgRatio);
+    return NS_RGBA(r, g, b, NS_GET_A(aFg));
+  }
+
+  constexpr float kFactor = 1.0f / 255.0f;
+
+  float p1 = kFactor * (255 - aFgRatio);
+  float a1 = kFactor * NS_GET_A(aBg);
+  float r1 = a1 * NS_GET_R(aBg);
+  float g1 = a1 * NS_GET_G(aBg);
+  float b1 = a1 * NS_GET_B(aBg);
+
+  float p2 = 1.0f - p1;
+  float a2 = kFactor * NS_GET_A(aFg);
+  float r2 = a2 * NS_GET_R(aFg);
+  float g2 = a2 * NS_GET_G(aFg);
+  float b2 = a2 * NS_GET_B(aFg);
+
+  float a = p1 * a1 + p2 * a2;
+  if (a == 0.0) {
+    return NS_RGBA(0, 0, 0, 0);
+  }
+
+  auto r = ClampColor((p1 * r1 + p2 * r2) / a);
+  auto g = ClampColor((p1 * g1 + p2 * g2) / a);
+  auto b = ClampColor((p1 * b1 + p2 * b2) / a);
+  return NS_RGBA(r, g, b, NSToIntRound(a * 255));
+}
+
+} // namespace mozilla
+
+// Functions to convert from HSL color space to RGB color space.
+// This is the algorithm described in the CSS3 specification
+
+// helper
+static float
+HSL_HueToRGB(float m1, float m2, float h)
+{
+  if (h < 0.0f)
+    h += 1.0f;
+  if (h > 1.0f)
+    h -= 1.0f;
+  if (h < (float)(1.0/6.0))
+    return m1 + (m2 - m1)*h*6.0f;
+  if (h < (float)(1.0/2.0))
+    return m2;
+  if (h < (float)(2.0/3.0))
+    return m1 + (m2 - m1)*((float)(2.0/3.0) - h)*6.0f;
+  return m1;      
+}
+
+// The float parameters are all expected to be in the range 0-1
+nscolor
+NS_HSL2RGB(float h, float s, float l)
+{
+  uint8_t r, g, b;
+  float m1, m2;
+  if (l <= 0.5f) {
+    m2 = l*(s+1);
+  } else {
+    m2 = l + s - l*s;
+  }
+  m1 = l*2 - m2;
+  r = uint8_t(255 * HSL_HueToRGB(m1, m2, h + 1.0f/3.0f));
+  g = uint8_t(255 * HSL_HueToRGB(m1, m2, h));
+  b = uint8_t(255 * HSL_HueToRGB(m1, m2, h - 1.0f/3.0f));
+  return NS_RGB(r, g, b);  
+}
+
+const char*
+NS_RGBToColorName(nscolor aColor)
+{
+  for (size_t idx = 0; idx < ArrayLength(kColors); ++idx) {
+    if (kColors[idx] == aColor) {
+      return kColorNames[idx];
+    }
+  }
+
+  return nullptr;
+}
diff --git a/gfx/src/nsColor.h b/gfx/src/nsColor.h
new file mode 100644
index 000000000..2f21c91bf
--- /dev/null
+++ b/gfx/src/nsColor.h
@@ -0,0 +1,123 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsColor_h___
+#define nsColor_h___
+
+#include <stddef.h>                     // for size_t
+#include <stdint.h>                     // for uint8_t, uint32_t
+#include "nscore.h"                     // for nsAString
+#include "nsCoord.h"                    // for NSToIntRound
+
+class nsAString;
+class nsString;
+
+// A color is a 32 bit unsigned integer with four components: R, G, B
+// and A.
+typedef uint32_t nscolor;
+
+// Make a color out of r,g,b values. This assumes that the r,g,b values are
+// properly constrained to 0-255. This also assumes that a is 255.
+#define NS_RGB(_r,_g,_b) \
+  ((nscolor) ((255 << 24) | ((_b)<<16) | ((_g)<<8) | (_r)))
+
+// Make a color out of r,g,b,a values. This assumes that the r,g,b,a
+// values are properly constrained to 0-255.
+#define NS_RGBA(_r,_g,_b,_a) \
+  ((nscolor) (((_a) << 24) | ((_b)<<16) | ((_g)<<8) | (_r)))
+
+// Extract color components from nscolor
+#define NS_GET_R(_rgba) ((uint8_t) ((_rgba) & 0xff))
+#define NS_GET_G(_rgba) ((uint8_t) (((_rgba) >> 8) & 0xff))
+#define NS_GET_B(_rgba) ((uint8_t) (((_rgba) >> 16) & 0xff))
+#define NS_GET_A(_rgba) ((uint8_t) (((_rgba) >> 24) & 0xff))
+
+namespace mozilla {
+
+template<typename T>
+inline uint8_t ClampColor(T aColor)
+{
+  if (aColor >= 255) {
+    return 255;
+  }
+  if (aColor <= 0) {
+    return 0;
+  }
+  return NSToIntRound(aColor);
+}
+
+} // namespace mozilla
+
+// Fast approximate division by 255. It has the property that
+// for all 0 <= n <= 255*255, FAST_DIVIDE_BY_255(n) == n/255.
+// But it only uses two adds and two shifts instead of an 
+// integer division (which is expensive on many processors).
+//
+// equivalent to target=v/255
+#define FAST_DIVIDE_BY_255(target,v)               \
+  PR_BEGIN_MACRO                                   \
+    unsigned tmp_ = v;                             \
+    target = ((tmp_ << 8) + tmp_ + 255) >> 16;     \
+  PR_END_MACRO
+
+enum class nsHexColorType : uint8_t {
+  NoAlpha, // 3 or 6 digit hex colors only
+  AllowAlpha, // 3, 4, 6, or 8 digit hex colors
+};
+
+// Translate a hex string to a color. Return true if it parses ok,
+// otherwise return false.
+// This accepts the number of digits specified by aType.
+bool
+NS_HexToRGBA(const nsAString& aBuf, nsHexColorType aType, nscolor* aResult);
+
+// Compose one NS_RGB color onto another. The result is what
+// you get if you draw aFG on top of aBG with operator OVER.
+nscolor NS_ComposeColors(nscolor aBG, nscolor aFG);
+
+namespace mozilla {
+
+inline uint32_t RoundingDivideBy255(uint32_t n)
+{
+  // There is an approximate alternative: ((n << 8) + n + 32896) >> 16
+  // But that is actually slower than this simple expression on a modern
+  // machine with a modern compiler.
+  return (n + 127) / 255;
+}
+
+// Blend one RGBA color with another based on a given ratio.
+// It is a linear interpolation on each channel with alpha premultipled.
+nscolor LinearBlendColors(nscolor aBg, nscolor aFg, uint_fast8_t aFgRatio);
+
+} // namespace mozilla
+
+// Translate a hex string to a color. Return true if it parses ok,
+// otherwise return false.
+// This version accepts 1 to 9 digits (missing digits are 0)
+bool NS_LooseHexToRGB(const nsString& aBuf, nscolor* aResult);
+
+// There is no function to translate a color to a hex string, because
+// the hex-string syntax does not support transparency.
+
+// Translate a color name to a color. Return true if it parses ok,
+// otherwise return false.
+bool NS_ColorNameToRGB(const nsAString& aBuf, nscolor* aResult);
+
+// Returns an array of all possible color names, and sets
+// *aSizeArray to the size of that array. Do NOT call |free()| on this array.
+const char * const * NS_AllColorNames(size_t *aSizeArray);
+
+// function to convert from HSL color space to RGB color space
+// the float parameters are all expected to be in the range 0-1
+nscolor NS_HSL2RGB(float h, float s, float l);
+
+// Return a color name for the given nscolor.  If there is no color
+// name for it, returns null.  If there are multiple possible color
+// names for the given color, the first one in nsColorNameList.h
+// (which is generally the first one in alphabetical order) will be
+// returned.
+const char* NS_RGBToColorName(nscolor aColor);
+
+#endif /* nsColor_h___ */
diff --git a/gfx/src/nsColorNameList.h b/gfx/src/nsColorNameList.h
new file mode 100644
index 000000000..b679b981d
--- /dev/null
+++ b/gfx/src/nsColorNameList.h
@@ -0,0 +1,181 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/******
+
+  This file contains the list of all named colors
+  See nsCSSColorNames.h for access to the enum values for colors
+
+  It is designed to be used as inline input to nsCSSColorNames.cpp *only*
+  through the magic of C preprocessing.
+
+  All entries must be enclosed in the macro GFX_COLOR which will have cruel
+  and unusual things done to it
+
+  It is recommended (but not strictly necessary) to keep all entries
+  in alphabetical order
+
+  The first argument to GFX_COLOR is both the enum identifier of the color
+  and the string value
+  The second argument is the sRGBA value for the named color
+
+  'name' entries *must* use only lowercase characters.
+
+  ** Break these invarient and bad things will happen. **
+
+
+ ******/
+
+
+GFX_COLOR(aliceblue, NS_RGB(240, 248, 255))
+GFX_COLOR(antiquewhite, NS_RGB(250, 235, 215))
+GFX_COLOR(aqua, NS_RGB(  0, 255, 255))
+GFX_COLOR(aquamarine, NS_RGB(127, 255, 212))
+GFX_COLOR(azure, NS_RGB(240, 255, 255))
+GFX_COLOR(beige, NS_RGB(245, 245, 220))
+GFX_COLOR(bisque, NS_RGB(255, 228, 196))
+GFX_COLOR(black, NS_RGB(  0,   0,   0))
+GFX_COLOR(blanchedalmond, NS_RGB(255, 235, 205))
+GFX_COLOR(blue, NS_RGB(  0,   0, 255))
+GFX_COLOR(blueviolet, NS_RGB(138,  43, 226))
+GFX_COLOR(brown, NS_RGB(165,  42,  42))
+GFX_COLOR(burlywood, NS_RGB(222, 184, 135))
+GFX_COLOR(cadetblue, NS_RGB( 95, 158, 160))
+GFX_COLOR(chartreuse, NS_RGB(127, 255,   0))
+GFX_COLOR(chocolate, NS_RGB(210, 105,  30))
+GFX_COLOR(coral, NS_RGB(255, 127,  80))
+GFX_COLOR(cornflowerblue, NS_RGB(100, 149, 237))
+GFX_COLOR(cornsilk, NS_RGB(255, 248, 220))
+GFX_COLOR(crimson, NS_RGB(220,  20,  60))
+GFX_COLOR(cyan, NS_RGB(  0, 255, 255))
+GFX_COLOR(darkblue, NS_RGB(  0,   0, 139))
+GFX_COLOR(darkcyan, NS_RGB(  0, 139, 139))
+GFX_COLOR(darkgoldenrod, NS_RGB(184, 134,  11))
+GFX_COLOR(darkgray, NS_RGB(169, 169, 169))
+GFX_COLOR(darkgreen, NS_RGB(  0, 100,   0))
+GFX_COLOR(darkgrey, NS_RGB(169, 169, 169))
+GFX_COLOR(darkkhaki, NS_RGB(189, 183, 107))
+GFX_COLOR(darkmagenta, NS_RGB(139,   0, 139))
+GFX_COLOR(darkolivegreen, NS_RGB( 85, 107,  47))
+GFX_COLOR(darkorange, NS_RGB(255, 140,   0))
+GFX_COLOR(darkorchid, NS_RGB(153,  50, 204))
+GFX_COLOR(darkred, NS_RGB(139,   0,   0))
+GFX_COLOR(darksalmon, NS_RGB(233, 150, 122))
+GFX_COLOR(darkseagreen, NS_RGB(143, 188, 143))
+GFX_COLOR(darkslateblue, NS_RGB( 72,  61, 139))
+GFX_COLOR(darkslategray, NS_RGB( 47,  79,  79))
+GFX_COLOR(darkslategrey, NS_RGB( 47,  79,  79))
+GFX_COLOR(darkturquoise, NS_RGB(  0, 206, 209))
+GFX_COLOR(darkviolet, NS_RGB(148,   0, 211))
+GFX_COLOR(deeppink, NS_RGB(255,  20, 147))
+GFX_COLOR(deepskyblue, NS_RGB(  0, 191, 255))
+GFX_COLOR(dimgray, NS_RGB(105, 105, 105))
+GFX_COLOR(dimgrey, NS_RGB(105, 105, 105))
+GFX_COLOR(dodgerblue, NS_RGB( 30, 144, 255))
+GFX_COLOR(firebrick, NS_RGB(178,  34,  34))
+GFX_COLOR(floralwhite, NS_RGB(255, 250, 240))
+GFX_COLOR(forestgreen, NS_RGB( 34, 139,  34))
+GFX_COLOR(fuchsia, NS_RGB(255,   0, 255))
+GFX_COLOR(gainsboro, NS_RGB(220, 220, 220))
+GFX_COLOR(ghostwhite, NS_RGB(248, 248, 255))
+GFX_COLOR(gold, NS_RGB(255, 215,   0))
+GFX_COLOR(goldenrod, NS_RGB(218, 165,  32))
+GFX_COLOR(gray, NS_RGB(128, 128, 128))
+GFX_COLOR(grey, NS_RGB(128, 128, 128))
+GFX_COLOR(green, NS_RGB(  0, 128,   0))
+GFX_COLOR(greenyellow, NS_RGB(173, 255,  47))
+GFX_COLOR(honeydew, NS_RGB(240, 255, 240))
+GFX_COLOR(hotpink, NS_RGB(255, 105, 180))
+GFX_COLOR(indianred, NS_RGB(205,  92,  92))
+GFX_COLOR(indigo, NS_RGB( 75,   0, 130))
+GFX_COLOR(ivory, NS_RGB(255, 255, 240))
+GFX_COLOR(khaki, NS_RGB(240, 230, 140))
+GFX_COLOR(lavender, NS_RGB(230, 230, 250))
+GFX_COLOR(lavenderblush, NS_RGB(255, 240, 245))
+GFX_COLOR(lawngreen, NS_RGB(124, 252,   0))
+GFX_COLOR(lemonchiffon, NS_RGB(255, 250, 205))
+GFX_COLOR(lightblue, NS_RGB(173, 216, 230))
+GFX_COLOR(lightcoral, NS_RGB(240, 128, 128))
+GFX_COLOR(lightcyan, NS_RGB(224, 255, 255))
+GFX_COLOR(lightgoldenrodyellow, NS_RGB(250, 250, 210))
+GFX_COLOR(lightgray, NS_RGB(211, 211, 211))
+GFX_COLOR(lightgreen, NS_RGB(144, 238, 144))
+GFX_COLOR(lightgrey, NS_RGB(211, 211, 211))
+GFX_COLOR(lightpink, NS_RGB(255, 182, 193))
+GFX_COLOR(lightsalmon, NS_RGB(255, 160, 122))
+GFX_COLOR(lightseagreen, NS_RGB( 32, 178, 170))
+GFX_COLOR(lightskyblue, NS_RGB(135, 206, 250))
+GFX_COLOR(lightslategray, NS_RGB(119, 136, 153))
+GFX_COLOR(lightslategrey, NS_RGB(119, 136, 153))
+GFX_COLOR(lightsteelblue, NS_RGB(176, 196, 222))
+GFX_COLOR(lightyellow, NS_RGB(255, 255, 224))
+GFX_COLOR(lime, NS_RGB(  0, 255,   0))
+GFX_COLOR(limegreen, NS_RGB( 50, 205,  50))
+GFX_COLOR(linen, NS_RGB(250, 240, 230))
+GFX_COLOR(magenta, NS_RGB(255,   0, 255))
+GFX_COLOR(maroon, NS_RGB(128,   0,   0))
+GFX_COLOR(mediumaquamarine, NS_RGB(102, 205, 170))
+GFX_COLOR(mediumblue, NS_RGB(  0,   0, 205))
+GFX_COLOR(mediumorchid, NS_RGB(186,  85, 211))
+GFX_COLOR(mediumpurple, NS_RGB(147, 112, 219))
+GFX_COLOR(mediumseagreen, NS_RGB( 60, 179, 113))
+GFX_COLOR(mediumslateblue, NS_RGB(123, 104, 238))
+GFX_COLOR(mediumspringgreen, NS_RGB(  0, 250, 154))
+GFX_COLOR(mediumturquoise, NS_RGB( 72, 209, 204))
+GFX_COLOR(mediumvioletred, NS_RGB(199,  21, 133))
+GFX_COLOR(midnightblue, NS_RGB( 25,  25, 112))
+GFX_COLOR(mintcream, NS_RGB(245, 255, 250))
+GFX_COLOR(mistyrose, NS_RGB(255, 228, 225))
+GFX_COLOR(moccasin, NS_RGB(255, 228, 181))
+GFX_COLOR(navajowhite, NS_RGB(255, 222, 173))
+GFX_COLOR(navy, NS_RGB(  0,   0, 128))
+GFX_COLOR(oldlace, NS_RGB(253, 245, 230))
+GFX_COLOR(olive, NS_RGB(128, 128,   0))
+GFX_COLOR(olivedrab, NS_RGB(107, 142,  35))
+GFX_COLOR(orange, NS_RGB(255, 165,   0))
+GFX_COLOR(orangered, NS_RGB(255,  69,   0))
+GFX_COLOR(orchid, NS_RGB(218, 112, 214))
+GFX_COLOR(palegoldenrod, NS_RGB(238, 232, 170))
+GFX_COLOR(palegreen, NS_RGB(152, 251, 152))
+GFX_COLOR(paleturquoise, NS_RGB(175, 238, 238))
+GFX_COLOR(palevioletred, NS_RGB(219, 112, 147))
+GFX_COLOR(papayawhip, NS_RGB(255, 239, 213))
+GFX_COLOR(peachpuff, NS_RGB(255, 218, 185))
+GFX_COLOR(peru, NS_RGB(205, 133,  63))
+GFX_COLOR(pink, NS_RGB(255, 192, 203))
+GFX_COLOR(plum, NS_RGB(221, 160, 221))
+GFX_COLOR(powderblue, NS_RGB(176, 224, 230))
+GFX_COLOR(purple, NS_RGB(128,   0, 128))
+GFX_COLOR(rebeccapurple, NS_RGB(102, 51, 153))
+GFX_COLOR(red, NS_RGB(255,   0,   0))
+GFX_COLOR(rosybrown, NS_RGB(188, 143, 143))
+GFX_COLOR(royalblue, NS_RGB( 65, 105, 225))
+GFX_COLOR(saddlebrown, NS_RGB(139,  69,  19))
+GFX_COLOR(salmon, NS_RGB(250, 128, 114))
+GFX_COLOR(sandybrown, NS_RGB(244, 164,  96))
+GFX_COLOR(seagreen, NS_RGB( 46, 139,  87))
+GFX_COLOR(seashell, NS_RGB(255, 245, 238))
+GFX_COLOR(sienna, NS_RGB(160,  82,  45))
+GFX_COLOR(silver, NS_RGB(192, 192, 192))
+GFX_COLOR(skyblue, NS_RGB(135, 206, 235))
+GFX_COLOR(slateblue, NS_RGB(106,  90, 205))
+GFX_COLOR(slategray, NS_RGB(112, 128, 144))
+GFX_COLOR(slategrey, NS_RGB(112, 128, 144))
+GFX_COLOR(snow, NS_RGB(255, 250, 250))
+GFX_COLOR(springgreen, NS_RGB(  0, 255, 127))
+GFX_COLOR(steelblue, NS_RGB( 70, 130, 180))
+GFX_COLOR(tan, NS_RGB(210, 180, 140))
+GFX_COLOR(teal, NS_RGB(  0, 128, 128))
+GFX_COLOR(thistle, NS_RGB(216, 191, 216))
+GFX_COLOR(tomato, NS_RGB(255,  99,  71))
+GFX_COLOR(transparent, NS_RGBA(0, 0, 0, 0))
+GFX_COLOR(turquoise, NS_RGB( 64, 224, 208))
+GFX_COLOR(violet, NS_RGB(238, 130, 238))
+GFX_COLOR(wheat, NS_RGB(245, 222, 179))
+GFX_COLOR(white, NS_RGB(255, 255, 255))
+GFX_COLOR(whitesmoke, NS_RGB(245, 245, 245))
+GFX_COLOR(yellow, NS_RGB(255, 255,   0))
+GFX_COLOR(yellowgreen, NS_RGB(154, 205,  50))
+
diff --git a/gfx/src/nsColorNames.h b/gfx/src/nsColorNames.h
new file mode 100644
index 000000000..388789710
--- /dev/null
+++ b/gfx/src/nsColorNames.h
@@ -0,0 +1,16 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsColorNames_h___
+#define nsColorNames_h___
+
+
+class nsColorNames {
+public:
+  static void AddRefTable(void);
+  static void ReleaseTable(void);
+};
+
+#endif /* nsColorNames_h___ */
diff --git a/gfx/src/nsCoord.h b/gfx/src/nsCoord.h
new file mode 100644
index 000000000..bb53611cf
--- /dev/null
+++ b/gfx/src/nsCoord.h
@@ -0,0 +1,443 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef NSCOORD_H
+#define NSCOORD_H
+
+#include "nsAlgorithm.h"
+#include "nscore.h"
+#include "nsMathUtils.h"
+#include <math.h>
+#include <float.h>
+#include <stdlib.h>
+
+#include "nsDebug.h"
+#include <algorithm>
+
+/*
+ * Basic type used for the geometry classes.
+ *
+ * Normally all coordinates are maintained in an app unit coordinate
+ * space. An app unit is 1/60th of a CSS device pixel, which is, in turn
+ * an integer number of device pixels, such at the CSS DPI is as close to
+ * 96dpi as possible.
+ */
+
+// This controls whether we're using integers or floats for coordinates. We
+// want to eventually use floats.
+//#define NS_COORD_IS_FLOAT
+
+inline float NS_IEEEPositiveInfinity() {
+  union { uint32_t mPRUint32; float mFloat; } pun;
+  pun.mPRUint32 = 0x7F800000;
+  return pun.mFloat;
+}
+inline bool NS_IEEEIsNan(float aF) {
+  union { uint32_t mBits; float mFloat; } pun;
+  pun.mFloat = aF;
+  return (pun.mBits & 0x7F800000) == 0x7F800000 &&
+    (pun.mBits & 0x007FFFFF) != 0;
+}
+
+#ifdef NS_COORD_IS_FLOAT
+typedef float nscoord;
+#define nscoord_MAX NS_IEEEPositiveInfinity()
+#else
+typedef int32_t nscoord;
+#define nscoord_MAX nscoord(1 << 30)
+#endif
+
+#define nscoord_MIN (-nscoord_MAX)
+
+inline void VERIFY_COORD(nscoord aCoord) {
+#ifdef NS_COORD_IS_FLOAT
+  NS_ASSERTION(floorf(aCoord) == aCoord,
+               "Coords cannot have fractions");
+#endif
+}
+
+/**
+ * Divide aSpace by aN.  Assign the resulting quotient to aQuotient and
+ * return the remainder.
+ */
+inline nscoord NSCoordDivRem(nscoord aSpace, size_t aN, nscoord* aQuotient)
+{
+#ifdef NS_COORD_IS_FLOAT
+  *aQuotient = aSpace / aN;
+  return 0.0f;
+#else
+  div_t result = div(aSpace, aN);
+  *aQuotient = nscoord(result.quot);
+  return nscoord(result.rem);
+#endif
+}
+
+inline nscoord NSCoordMulDiv(nscoord aMult1, nscoord aMult2, nscoord aDiv) {
+#ifdef NS_COORD_IS_FLOAT
+  return (aMult1 * aMult2 / aDiv);
+#else
+  return (int64_t(aMult1) * int64_t(aMult2) / int64_t(aDiv));
+#endif
+}
+
+inline nscoord NSToCoordRound(float aValue)
+{
+#if defined(XP_WIN32) && defined(_M_IX86) && !defined(__GNUC__) && !defined(__clang__)
+  return NS_lroundup30(aValue);
+#else
+  return nscoord(floorf(aValue + 0.5f));
+#endif /* XP_WIN32 && _M_IX86 && !__GNUC__ */
+}
+
+inline nscoord NSToCoordRound(double aValue)
+{
+#if defined(XP_WIN32) && defined(_M_IX86) && !defined(__GNUC__) && !defined(__clang__)
+  return NS_lroundup30((float)aValue);
+#else
+  return nscoord(floor(aValue + 0.5f));
+#endif /* XP_WIN32 && _M_IX86 && !__GNUC__ */
+}
+
+inline nscoord NSToCoordRoundWithClamp(float aValue)
+{
+#ifndef NS_COORD_IS_FLOAT
+  // Bounds-check before converting out of float, to avoid overflow
+  if (aValue >= nscoord_MAX) {
+    return nscoord_MAX;
+  }
+  if (aValue <= nscoord_MIN) {
+    return nscoord_MIN;
+  }
+#endif
+  return NSToCoordRound(aValue);
+}
+
+/**
+ * Returns aCoord * aScale, capping the product to nscoord_MAX or nscoord_MIN as
+ * appropriate for the signs of aCoord and aScale.  If requireNotNegative is
+ * true, this method will enforce that aScale is not negative; use that
+ * parametrization to get a check of that fact in debug builds.
+ */
+inline nscoord _nscoordSaturatingMultiply(nscoord aCoord, float aScale,
+                                          bool requireNotNegative) {
+  VERIFY_COORD(aCoord);
+  if (requireNotNegative) {
+    MOZ_ASSERT(aScale >= 0.0f,
+               "negative scaling factors must be handled manually");
+  }
+#ifdef NS_COORD_IS_FLOAT
+  return floorf(aCoord * aScale);
+#else
+  float product = aCoord * aScale;
+  if (requireNotNegative ? aCoord > 0 : (aCoord > 0) == (aScale > 0))
+    return NSToCoordRoundWithClamp(std::min<float>(nscoord_MAX, product));
+  return NSToCoordRoundWithClamp(std::max<float>(nscoord_MIN, product));
+#endif
+}
+
+/**
+ * Returns aCoord * aScale, capping the product to nscoord_MAX or nscoord_MIN as
+ * appropriate for the sign of aCoord.  This method requires aScale to not be
+ * negative; use this method when you know that aScale should never be
+ * negative to get a sanity check of that invariant in debug builds.
+ */
+inline nscoord NSCoordSaturatingNonnegativeMultiply(nscoord aCoord, float aScale) {
+  return _nscoordSaturatingMultiply(aCoord, aScale, true);
+}
+
+/**
+ * Returns aCoord * aScale, capping the product to nscoord_MAX or nscoord_MIN as
+ * appropriate for the signs of aCoord and aScale.
+ */
+inline nscoord NSCoordSaturatingMultiply(nscoord aCoord, float aScale) {
+  return _nscoordSaturatingMultiply(aCoord, aScale, false);
+}
+
+/**
+ * Returns a + b, capping the sum to nscoord_MAX.
+ *
+ * This function assumes that neither argument is nscoord_MIN.
+ *
+ * Note: If/when we start using floats for nscoords, this function won't be as
+ * necessary.  Normal float addition correctly handles adding with infinity,
+ * assuming we aren't adding nscoord_MIN. (-infinity)
+ */
+inline nscoord
+NSCoordSaturatingAdd(nscoord a, nscoord b)
+{
+  VERIFY_COORD(a);
+  VERIFY_COORD(b);
+
+#ifdef NS_COORD_IS_FLOAT
+  // Float math correctly handles a+b, given that neither is -infinity.
+  return a + b;
+#else
+  if (a == nscoord_MAX || b == nscoord_MAX) {
+    // infinity + anything = anything + infinity = infinity
+    return nscoord_MAX;
+  } else {
+    // a + b = a + b
+    // Cap the result, just in case we're dealing with numbers near nscoord_MAX
+    return std::min(nscoord_MAX, a + b);
+  }
+#endif
+}
+
+/**
+ * Returns a - b, gracefully handling cases involving nscoord_MAX.
+ * This function assumes that neither argument is nscoord_MIN.
+ *
+ * The behavior is as follows:
+ *
+ *  a)  infinity - infinity -> infMinusInfResult
+ *  b)  N - infinity        -> 0  (unexpected -- triggers NOTREACHED)
+ *  c)  infinity - N        -> infinity
+ *  d)  N1 - N2             -> N1 - N2
+ *
+ * Note: For float nscoords, cases (c) and (d) are handled by normal float
+ * math.  We still need to explicitly specify the behavior for cases (a)
+ * and (b), though.  (Under normal float math, those cases would return NaN
+ * and -infinity, respectively.)
+ */
+inline nscoord 
+NSCoordSaturatingSubtract(nscoord a, nscoord b, 
+                          nscoord infMinusInfResult)
+{
+  VERIFY_COORD(a);
+  VERIFY_COORD(b);
+
+  if (b == nscoord_MAX) {
+    if (a == nscoord_MAX) {
+      // case (a)
+      return infMinusInfResult;
+    } else {
+      // case (b)
+      NS_NOTREACHED("Attempted to subtract [n - nscoord_MAX]");
+      return 0;
+    }
+  } else {
+#ifdef NS_COORD_IS_FLOAT
+    // case (c) and (d) for floats.  (float math handles both)
+    return a - b;
+#else
+    if (a == nscoord_MAX) {
+      // case (c) for integers
+      return nscoord_MAX;
+    } else {
+      // case (d) for integers
+      // Cap the result, in case we're dealing with numbers near nscoord_MAX
+      return std::min(nscoord_MAX, a - b);
+    }
+#endif
+  }
+}
+
+inline float NSCoordToFloat(nscoord aCoord) {
+  VERIFY_COORD(aCoord);
+#ifdef NS_COORD_IS_FLOAT
+  NS_ASSERTION(!NS_IEEEIsNan(aCoord), "NaN encountered in float conversion");
+#endif
+  return (float)aCoord;
+}
+
+/*
+ * Coord Rounding Functions
+ */
+inline nscoord NSToCoordFloor(float aValue)
+{
+  return nscoord(floorf(aValue));
+}
+
+inline nscoord NSToCoordFloor(double aValue)
+{
+  return nscoord(floor(aValue));
+}
+
+inline nscoord NSToCoordFloorClamped(float aValue)
+{
+#ifndef NS_COORD_IS_FLOAT
+  // Bounds-check before converting out of float, to avoid overflow
+  if (aValue >= nscoord_MAX) {
+    return nscoord_MAX;
+  }
+  if (aValue <= nscoord_MIN) {
+    return nscoord_MIN;
+  }
+#endif
+  return NSToCoordFloor(aValue);
+}
+
+inline nscoord NSToCoordCeil(float aValue)
+{
+  return nscoord(ceilf(aValue));
+}
+
+inline nscoord NSToCoordCeil(double aValue)
+{
+  return nscoord(ceil(aValue));
+}
+
+inline nscoord NSToCoordCeilClamped(double aValue)
+{
+#ifndef NS_COORD_IS_FLOAT
+  // Bounds-check before converting out of double, to avoid overflow
+  if (aValue >= nscoord_MAX) {
+    return nscoord_MAX;
+  }
+  if (aValue <= nscoord_MIN) {
+    return nscoord_MIN;
+  }
+#endif
+  return NSToCoordCeil(aValue);
+}
+
+// The NSToCoordTrunc* functions remove the fractional component of
+// aValue, and are thus equivalent to NSToCoordFloor* for positive
+// values and NSToCoordCeil* for negative values.
+
+inline nscoord NSToCoordTrunc(float aValue)
+{
+  // There's no need to use truncf() since it matches the default
+  // rules for float to integer conversion.
+  return nscoord(aValue);
+}
+
+inline nscoord NSToCoordTrunc(double aValue)
+{
+  // There's no need to use trunc() since it matches the default
+  // rules for float to integer conversion.
+  return nscoord(aValue);
+}
+
+inline nscoord NSToCoordTruncClamped(float aValue)
+{
+#ifndef NS_COORD_IS_FLOAT
+  // Bounds-check before converting out of float, to avoid overflow
+  if (aValue >= nscoord_MAX) {
+    return nscoord_MAX;
+  }
+  if (aValue <= nscoord_MIN) {
+    return nscoord_MIN;
+  }
+#endif
+  return NSToCoordTrunc(aValue);
+}
+
+inline nscoord NSToCoordTruncClamped(double aValue)
+{
+#ifndef NS_COORD_IS_FLOAT
+  // Bounds-check before converting out of double, to avoid overflow
+  if (aValue >= nscoord_MAX) {
+    return nscoord_MAX;
+  }
+  if (aValue <= nscoord_MIN) {
+    return nscoord_MIN;
+  }
+#endif
+  return NSToCoordTrunc(aValue);
+}
+
+/*
+ * Int Rounding Functions
+ */
+inline int32_t NSToIntFloor(float aValue)
+{
+  return int32_t(floorf(aValue));
+}
+
+inline int32_t NSToIntCeil(float aValue)
+{
+  return int32_t(ceilf(aValue));
+}
+
+inline int32_t NSToIntRound(float aValue)
+{
+  return NS_lroundf(aValue);
+}
+
+inline int32_t NSToIntRound(double aValue)
+{
+  return NS_lround(aValue);
+}
+
+inline int32_t NSToIntRoundUp(double aValue)
+{
+  return int32_t(floor(aValue + 0.5));
+}
+
+/* 
+ * App Unit/Pixel conversions
+ */
+inline nscoord NSFloatPixelsToAppUnits(float aPixels, float aAppUnitsPerPixel)
+{
+  return NSToCoordRoundWithClamp(aPixels * aAppUnitsPerPixel);
+}
+
+inline nscoord NSIntPixelsToAppUnits(int32_t aPixels, int32_t aAppUnitsPerPixel)
+{
+  // The cast to nscoord makes sure we don't overflow if we ever change
+  // nscoord to float
+  nscoord r = aPixels * (nscoord)aAppUnitsPerPixel;
+  VERIFY_COORD(r);
+  return r;
+}
+
+inline float NSAppUnitsToFloatPixels(nscoord aAppUnits, float aAppUnitsPerPixel)
+{
+  return (float(aAppUnits) / aAppUnitsPerPixel);
+}
+
+inline double NSAppUnitsToDoublePixels(nscoord aAppUnits, double aAppUnitsPerPixel)
+{
+  return (double(aAppUnits) / aAppUnitsPerPixel);
+}
+
+inline int32_t NSAppUnitsToIntPixels(nscoord aAppUnits, float aAppUnitsPerPixel)
+{
+  return NSToIntRound(float(aAppUnits) / aAppUnitsPerPixel);
+}
+
+inline float NSCoordScale(nscoord aCoord, int32_t aFromAPP, int32_t aToAPP)
+{
+  return (NSCoordToFloat(aCoord) * aToAPP) / aFromAPP;
+}
+
+/// handy constants
+#define TWIPS_PER_POINT_INT           20
+#define TWIPS_PER_POINT_FLOAT         20.0f
+#define POINTS_PER_INCH_INT           72
+#define POINTS_PER_INCH_FLOAT         72.0f
+#define CM_PER_INCH_FLOAT             2.54f
+#define MM_PER_INCH_FLOAT             25.4f
+
+/* 
+ * Twips/unit conversions
+ */
+inline float NSUnitsToTwips(float aValue, float aPointsPerUnit)
+{
+  return aValue * aPointsPerUnit * TWIPS_PER_POINT_FLOAT;
+}
+
+inline float NSTwipsToUnits(float aTwips, float aUnitsPerPoint)
+{
+  return (aTwips * (aUnitsPerPoint / TWIPS_PER_POINT_FLOAT));
+}
+
+/// Unit conversion macros
+//@{
+#define NS_POINTS_TO_TWIPS(x)         NSUnitsToTwips((x), 1.0f)
+#define NS_INCHES_TO_TWIPS(x)         NSUnitsToTwips((x), POINTS_PER_INCH_FLOAT)                      // 72 points per inch
+
+#define NS_MILLIMETERS_TO_TWIPS(x)    NSUnitsToTwips((x), (POINTS_PER_INCH_FLOAT * 0.03937f))
+
+#define NS_POINTS_TO_INT_TWIPS(x)     NSToIntRound(NS_POINTS_TO_TWIPS(x))
+#define NS_INCHES_TO_INT_TWIPS(x)     NSToIntRound(NS_INCHES_TO_TWIPS(x))
+
+#define NS_TWIPS_TO_INCHES(x)         NSTwipsToUnits((x), 1.0f / POINTS_PER_INCH_FLOAT)
+
+#define NS_TWIPS_TO_MILLIMETERS(x)    NSTwipsToUnits((x), 1.0f / (POINTS_PER_INCH_FLOAT * 0.03937f))
+//@}
+
+#endif /* NSCOORD_H */
diff --git a/gfx/src/nsDeviceContext.cpp b/gfx/src/nsDeviceContext.cpp
new file mode 100644
index 000000000..8a5c16973
--- /dev/null
+++ b/gfx/src/nsDeviceContext.cpp
@@ -0,0 +1,725 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* vim: set sw=4 ts=4 expandtab: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsDeviceContext.h"
+#include <algorithm>                    // for max
+#include "gfxASurface.h"                // for gfxASurface, etc
+#include "gfxContext.h"
+#include "gfxFont.h"                    // for gfxFontGroup
+#include "gfxImageSurface.h"            // for gfxImageSurface
+#include "gfxPoint.h"                   // for gfxSize
+#include "mozilla/Attributes.h"         // for final
+#include "mozilla/gfx/PathHelpers.h"
+#include "mozilla/gfx/PrintTarget.h"
+#include "mozilla/Preferences.h"        // for Preferences
+#include "mozilla/Services.h"           // for GetObserverService
+#include "mozilla/mozalloc.h"           // for operator new
+#include "nsCRT.h"                      // for nsCRT
+#include "nsDebug.h"                    // for NS_NOTREACHED, NS_ASSERTION, etc
+#include "nsFont.h"                     // for nsFont
+#include "nsFontMetrics.h"              // for nsFontMetrics
+#include "nsIAtom.h"                    // for nsIAtom, NS_Atomize
+#include "nsID.h"
+#include "nsIDeviceContextSpec.h"       // for nsIDeviceContextSpec
+#include "nsILanguageAtomService.h"     // for nsILanguageAtomService, etc
+#include "nsIObserver.h"                // for nsIObserver, etc
+#include "nsIObserverService.h"         // for nsIObserverService
+#include "nsIScreen.h"                  // for nsIScreen
+#include "nsIScreenManager.h"           // for nsIScreenManager
+#include "nsISupportsImpl.h"            // for MOZ_COUNT_CTOR, etc
+#include "nsISupportsUtils.h"           // for NS_ADDREF, NS_RELEASE
+#include "nsIWidget.h"                  // for nsIWidget, NS_NATIVE_WINDOW
+#include "nsRect.h"                     // for nsRect
+#include "nsServiceManagerUtils.h"      // for do_GetService
+#include "nsString.h"               // for nsDependentString
+#include "nsTArray.h"                   // for nsTArray, nsTArray_Impl
+#include "nsThreadUtils.h"              // for NS_IsMainThread
+#include "mozilla/gfx/Logging.h"
+
+using namespace mozilla;
+using namespace mozilla::gfx;
+using mozilla::services::GetObserverService;
+
+class nsFontCache final : public nsIObserver
+{
+public:
+    nsFontCache()   { MOZ_COUNT_CTOR(nsFontCache); }
+
+    NS_DECL_ISUPPORTS
+    NS_DECL_NSIOBSERVER
+
+    void Init(nsDeviceContext* aContext);
+    void Destroy();
+
+    already_AddRefed<nsFontMetrics> GetMetricsFor(
+        const nsFont& aFont, const nsFontMetrics::Params& aParams);
+
+    void FontMetricsDeleted(const nsFontMetrics* aFontMetrics);
+    void Compact();
+    void Flush();
+
+protected:
+    ~nsFontCache()  { MOZ_COUNT_DTOR(nsFontCache); }
+
+    nsDeviceContext*          mContext; // owner
+    nsCOMPtr<nsIAtom>         mLocaleLanguage;
+    nsTArray<nsFontMetrics*>  mFontMetrics;
+};
+
+NS_IMPL_ISUPPORTS(nsFontCache, nsIObserver)
+
+// The Init and Destroy methods are necessary because it's not
+// safe to call AddObserver from a constructor or RemoveObserver
+// from a destructor.  That should be fixed.
+void
+nsFontCache::Init(nsDeviceContext* aContext)
+{
+    mContext = aContext;
+    // register as a memory-pressure observer to free font resources
+    // in low-memory situations.
+    nsCOMPtr<nsIObserverService> obs = GetObserverService();
+    if (obs)
+        obs->AddObserver(this, "memory-pressure", false);
+
+    nsCOMPtr<nsILanguageAtomService> langService;
+    langService = do_GetService(NS_LANGUAGEATOMSERVICE_CONTRACTID);
+    if (langService) {
+        mLocaleLanguage = langService->GetLocaleLanguage();
+    }
+    if (!mLocaleLanguage) {
+        mLocaleLanguage = NS_Atomize("x-western");
+    }
+}
+
+void
+nsFontCache::Destroy()
+{
+    nsCOMPtr<nsIObserverService> obs = GetObserverService();
+    if (obs)
+        obs->RemoveObserver(this, "memory-pressure");
+    Flush();
+}
+
+NS_IMETHODIMP
+nsFontCache::Observe(nsISupports*, const char* aTopic, const char16_t*)
+{
+    if (!nsCRT::strcmp(aTopic, "memory-pressure"))
+        Compact();
+    return NS_OK;
+}
+
+already_AddRefed<nsFontMetrics>
+nsFontCache::GetMetricsFor(const nsFont& aFont,
+                           const nsFontMetrics::Params& aParams)
+{
+    nsIAtom* language = aParams.language ? aParams.language
+                                         : mLocaleLanguage.get();
+
+    // First check our cache
+    // start from the end, which is where we put the most-recent-used element
+
+    int32_t n = mFontMetrics.Length() - 1;
+    for (int32_t i = n; i >= 0; --i) {
+        nsFontMetrics* fm = mFontMetrics[i];
+        if (fm->Font().Equals(aFont) &&
+            fm->GetUserFontSet() == aParams.userFontSet &&
+            fm->Language() == language &&
+            fm->Orientation() == aParams.orientation) {
+            if (i != n) {
+                // promote it to the end of the cache
+                mFontMetrics.RemoveElementAt(i);
+                mFontMetrics.AppendElement(fm);
+            }
+            fm->GetThebesFontGroup()->UpdateUserFonts();
+            return do_AddRef(fm);
+        }
+    }
+
+    // It's not in the cache. Get font metrics and then cache them.
+
+    nsFontMetrics::Params params = aParams;
+    params.language = language;
+    RefPtr<nsFontMetrics> fm = new nsFontMetrics(aFont, params, mContext);
+    // the mFontMetrics list has the "head" at the end, because append
+    // is cheaper than insert
+    mFontMetrics.AppendElement(do_AddRef(fm.get()).take());
+    return fm.forget();
+}
+
+void
+nsFontCache::FontMetricsDeleted(const nsFontMetrics* aFontMetrics)
+{
+    mFontMetrics.RemoveElement(aFontMetrics);
+}
+
+void
+nsFontCache::Compact()
+{
+    // Need to loop backward because the running element can be removed on
+    // the way
+    for (int32_t i = mFontMetrics.Length()-1; i >= 0; --i) {
+        nsFontMetrics* fm = mFontMetrics[i];
+        nsFontMetrics* oldfm = fm;
+        // Destroy() isn't here because we want our device context to be
+        // notified
+        NS_RELEASE(fm); // this will reset fm to nullptr
+        // if the font is really gone, it would have called back in
+        // FontMetricsDeleted() and would have removed itself
+        if (mFontMetrics.IndexOf(oldfm) != mFontMetrics.NoIndex) {
+            // nope, the font is still there, so let's hold onto it too
+            NS_ADDREF(oldfm);
+        }
+    }
+}
+
+void
+nsFontCache::Flush()
+{
+    for (int32_t i = mFontMetrics.Length()-1; i >= 0; --i) {
+        nsFontMetrics* fm = mFontMetrics[i];
+        // Destroy() will unhook our device context from the fm so that we
+        // won't waste time in triggering the notification of
+        // FontMetricsDeleted() in the subsequent release
+        fm->Destroy();
+        NS_RELEASE(fm);
+    }
+    mFontMetrics.Clear();
+}
+
+nsDeviceContext::nsDeviceContext()
+    : mWidth(0), mHeight(0), mDepth(0),
+      mAppUnitsPerDevPixel(-1), mAppUnitsPerDevPixelAtUnitFullZoom(-1),
+      mAppUnitsPerPhysicalInch(-1),
+      mFullZoom(1.0f), mPrintingScale(1.0f)
+#ifdef DEBUG
+    , mIsInitialized(false)
+#endif
+{
+    MOZ_ASSERT(NS_IsMainThread(), "nsDeviceContext created off main thread");
+}
+
+nsDeviceContext::~nsDeviceContext()
+{
+    if (mFontCache) {
+        mFontCache->Destroy();
+    }
+}
+
+already_AddRefed<nsFontMetrics>
+nsDeviceContext::GetMetricsFor(const nsFont& aFont,
+                               const nsFontMetrics::Params& aParams)
+{
+    if (!mFontCache) {
+        mFontCache = new nsFontCache();
+        mFontCache->Init(this);
+    }
+
+    return mFontCache->GetMetricsFor(aFont, aParams);
+}
+
+nsresult
+nsDeviceContext::FlushFontCache(void)
+{
+    if (mFontCache)
+        mFontCache->Flush();
+    return NS_OK;
+}
+
+nsresult
+nsDeviceContext::FontMetricsDeleted(const nsFontMetrics* aFontMetrics)
+{
+    if (mFontCache) {
+        mFontCache->FontMetricsDeleted(aFontMetrics);
+    }
+    return NS_OK;
+}
+
+bool
+nsDeviceContext::IsPrinterContext()
+{
+  return mPrintTarget != nullptr
+#ifdef XP_MACOSX
+         || mCachedPrintTarget != nullptr
+#endif
+         ;
+}
+
+void
+nsDeviceContext::SetDPI(double* aScale)
+{
+    float dpi = -1.0f;
+
+    // Use the printing DC to determine DPI values, if we have one.
+    if (mDeviceContextSpec) {
+        dpi = mDeviceContextSpec->GetDPI();
+        mPrintingScale = mDeviceContextSpec->GetPrintingScale();
+        mAppUnitsPerDevPixelAtUnitFullZoom =
+            NS_lround((AppUnitsPerCSSPixel() * 96) / dpi);
+    } else {
+        // A value of -1 means use the maximum of 96 and the system DPI.
+        // A value of 0 means use the system DPI. A positive value is used as the DPI.
+        // This sets the physical size of a device pixel and thus controls the
+        // interpretation of physical units.
+        int32_t prefDPI = Preferences::GetInt("layout.css.dpi", -1);
+
+        if (prefDPI > 0) {
+            dpi = prefDPI;
+        } else if (mWidget) {
+            dpi = mWidget->GetDPI();
+
+            if (prefDPI < 0) {
+                dpi = std::max(96.0f, dpi);
+            }
+        } else {
+            dpi = 96.0f;
+        }
+
+        double devPixelsPerCSSPixel;
+        if (aScale && *aScale > 0.0) {
+            // if caller provided a scale, we just use it
+            devPixelsPerCSSPixel = *aScale;
+        } else {
+            // otherwise get from the widget, and return it in aScale for
+            // the caller to pass to child contexts if needed
+            CSSToLayoutDeviceScale scale =
+                mWidget ? mWidget->GetDefaultScale()
+                        : CSSToLayoutDeviceScale(1.0);
+            devPixelsPerCSSPixel = scale.scale;
+            if (aScale) {
+                *aScale = devPixelsPerCSSPixel;
+            }
+        }
+
+        mAppUnitsPerDevPixelAtUnitFullZoom =
+            std::max(1, NS_lround(AppUnitsPerCSSPixel() / devPixelsPerCSSPixel));
+    }
+
+    NS_ASSERTION(dpi != -1.0, "no dpi set");
+
+    mAppUnitsPerPhysicalInch = NS_lround(dpi * mAppUnitsPerDevPixelAtUnitFullZoom);
+    UpdateAppUnitsForFullZoom();
+}
+
+nsresult
+nsDeviceContext::Init(nsIWidget *aWidget)
+{
+#ifdef DEBUG
+    // We can't assert |!mIsInitialized| here since EndSwapDocShellsForDocument
+    // re-initializes nsDeviceContext objects.  We can only assert in
+    // InitForPrinting (below).
+    mIsInitialized = true;
+#endif
+
+    nsresult rv = NS_OK;
+    if (mScreenManager && mWidget == aWidget)
+        return rv;
+
+    mWidget = aWidget;
+    SetDPI();
+
+    if (mScreenManager)
+        return rv;
+
+    mScreenManager = do_GetService("@mozilla.org/gfx/screenmanager;1", &rv);
+
+    return rv;
+}
+
+// XXX This is only for printing. We should make that obvious in the name.
+already_AddRefed<gfxContext>
+nsDeviceContext::CreateRenderingContext()
+{
+  return CreateRenderingContextCommon(/* not a reference context */ false);
+}
+
+already_AddRefed<gfxContext>
+nsDeviceContext::CreateReferenceRenderingContext()
+{
+  return CreateRenderingContextCommon(/* a reference context */ true);
+}
+
+already_AddRefed<gfxContext>
+nsDeviceContext::CreateRenderingContextCommon(bool aWantReferenceContext)
+{
+    MOZ_ASSERT(IsPrinterContext());
+    MOZ_ASSERT(mWidth > 0 && mHeight > 0);
+
+    RefPtr<PrintTarget> printingTarget = mPrintTarget;
+#ifdef XP_MACOSX
+    // CreateRenderingContext() can be called (on reflow) after EndPage()
+    // but before BeginPage().  On OS X (and only there) mPrintTarget
+    // will in this case be null, because OS X printing surfaces are
+    // per-page, and therefore only truly valid between calls to BeginPage()
+    // and EndPage().  But we can get away with fudging things here, if need
+    // be, by using a cached copy.
+    if (!printingTarget) {
+      printingTarget = mCachedPrintTarget;
+    }
+#endif
+
+    // This will usually be null, depending on the pref print.print_via_parent.
+    RefPtr<DrawEventRecorder> recorder;
+    mDeviceContextSpec->GetDrawEventRecorder(getter_AddRefs(recorder));
+
+    RefPtr<gfx::DrawTarget> dt;
+    if (aWantReferenceContext) {
+      dt = printingTarget->GetReferenceDrawTarget(recorder);
+    } else {
+      dt = printingTarget->MakeDrawTarget(gfx::IntSize(mWidth, mHeight), recorder);
+    }
+
+    if (!dt || !dt->IsValid()) {
+      gfxCriticalNote
+        << "Failed to create draw target in device context sized "
+        << mWidth << "x" << mHeight << " and pointers "
+        << hexa(mPrintTarget) << " and " << hexa(printingTarget);
+      return nullptr;
+    }
+
+#ifdef XP_MACOSX
+    dt->AddUserData(&gfxContext::sDontUseAsSourceKey, dt, nullptr);
+#endif
+    dt->AddUserData(&sDisablePixelSnapping, (void*)0x1, nullptr);
+
+    RefPtr<gfxContext> pContext = gfxContext::CreateOrNull(dt);
+    MOZ_ASSERT(pContext); // already checked draw target above
+
+    gfxMatrix transform;
+    if (printingTarget->RotateNeededForLandscape()) {
+      // Rotate page 90 degrees to draw landscape page on portrait paper
+      IntSize size = printingTarget->GetSize();
+      transform.Translate(gfxPoint(0, size.width));
+      gfxMatrix rotate(0, -1,
+                       1,  0,
+                       0,  0);
+      transform = rotate * transform;
+    }
+    transform.Scale(mPrintingScale, mPrintingScale);
+
+    pContext->SetMatrix(transform);
+    return pContext.forget();
+}
+
+nsresult
+nsDeviceContext::GetDepth(uint32_t& aDepth)
+{
+    if (mDepth == 0 && mScreenManager) {
+        nsCOMPtr<nsIScreen> primaryScreen;
+        mScreenManager->GetPrimaryScreen(getter_AddRefs(primaryScreen));
+        primaryScreen->GetColorDepth(reinterpret_cast<int32_t *>(&mDepth));
+    }
+
+    aDepth = mDepth;
+    return NS_OK;
+}
+
+nsresult
+nsDeviceContext::GetDeviceSurfaceDimensions(nscoord &aWidth, nscoord &aHeight)
+{
+    if (IsPrinterContext()) {
+        aWidth = mWidth;
+        aHeight = mHeight;
+    } else {
+        nsRect area;
+        ComputeFullAreaUsingScreen(&area);
+        aWidth = area.width;
+        aHeight = area.height;
+    }
+
+    return NS_OK;
+}
+
+nsresult
+nsDeviceContext::GetRect(nsRect &aRect)
+{
+    if (IsPrinterContext()) {
+        aRect.x = 0;
+        aRect.y = 0;
+        aRect.width = mWidth;
+        aRect.height = mHeight;
+    } else
+        ComputeFullAreaUsingScreen ( &aRect );
+
+    return NS_OK;
+}
+
+nsresult
+nsDeviceContext::GetClientRect(nsRect &aRect)
+{
+    if (IsPrinterContext()) {
+        aRect.x = 0;
+        aRect.y = 0;
+        aRect.width = mWidth;
+        aRect.height = mHeight;
+    }
+    else
+        ComputeClientRectUsingScreen(&aRect);
+
+    return NS_OK;
+}
+
+nsresult
+nsDeviceContext::InitForPrinting(nsIDeviceContextSpec *aDevice)
+{
+    NS_ENSURE_ARG_POINTER(aDevice);
+
+    MOZ_ASSERT(!mIsInitialized,
+               "Only initialize once, immediately after construction");
+
+    // We don't set mIsInitialized here. The Init() call below does that.
+
+    mPrintTarget = aDevice->MakePrintTarget();
+    if (!mPrintTarget) {
+        return NS_ERROR_FAILURE;
+    }
+
+    mDeviceContextSpec = aDevice;
+
+    Init(nullptr);
+
+    if (!CalcPrintingSize()) {
+        return NS_ERROR_FAILURE;
+    }
+
+    return NS_OK;
+}
+
+nsresult
+nsDeviceContext::BeginDocument(const nsAString& aTitle,
+                               const nsAString& aPrintToFileName,
+                               int32_t          aStartPage,
+                               int32_t          aEndPage)
+{
+    nsresult rv = mPrintTarget->BeginPrinting(aTitle, aPrintToFileName);
+
+    if (NS_SUCCEEDED(rv) && mDeviceContextSpec) {
+      rv = mDeviceContextSpec->BeginDocument(aTitle, aPrintToFileName,
+                                             aStartPage, aEndPage);
+    }
+
+    return rv;
+}
+
+
+nsresult
+nsDeviceContext::EndDocument(void)
+{
+    nsresult rv = NS_OK;
+
+    if (mPrintTarget) {
+        rv = mPrintTarget->EndPrinting();
+        if (NS_SUCCEEDED(rv))
+            mPrintTarget->Finish();
+    }
+
+    if (mDeviceContextSpec)
+        mDeviceContextSpec->EndDocument();
+
+    return rv;
+}
+
+
+nsresult
+nsDeviceContext::AbortDocument(void)
+{
+    nsresult rv = mPrintTarget->AbortPrinting();
+
+    if (mDeviceContextSpec)
+        mDeviceContextSpec->EndDocument();
+
+    return rv;
+}
+
+
+nsresult
+nsDeviceContext::BeginPage(void)
+{
+    nsresult rv = NS_OK;
+
+    if (mDeviceContextSpec)
+        rv = mDeviceContextSpec->BeginPage();
+
+    if (NS_FAILED(rv)) return rv;
+
+#ifdef XP_MACOSX
+    // We need to get a new surface for each page on the Mac, as the
+    // CGContextRefs are only good for one page.
+    mPrintTarget = mDeviceContextSpec->MakePrintTarget();
+#endif
+
+    rv = mPrintTarget->BeginPage();
+
+    return rv;
+}
+
+nsresult
+nsDeviceContext::EndPage(void)
+{
+    nsresult rv = mPrintTarget->EndPage();
+
+#ifdef XP_MACOSX
+    // We need to release the CGContextRef in the surface here, plus it's
+    // not something you would want anyway, as these CGContextRefs are only
+    // good for one page.  But we need to keep a cached reference to it, since
+    // CreateRenderingContext() may try to access it when mPrintTarget
+    // would normally be null.  See bug 665218.  If we just stop nulling out
+    // mPrintTarget here (and thereby make that our cached copy), we'll
+    // break all our null checks on mPrintTarget.  See bug 684622.
+    mCachedPrintTarget = mPrintTarget;
+    mPrintTarget = nullptr;
+#endif
+
+    if (mDeviceContextSpec)
+        mDeviceContextSpec->EndPage();
+
+    return rv;
+}
+
+void
+nsDeviceContext::ComputeClientRectUsingScreen(nsRect* outRect)
+{
+    // we always need to recompute the clientRect
+    // because the window may have moved onto a different screen. In the single
+    // monitor case, we only need to do the computation if we haven't done it
+    // once already, and remember that we have because we're assured it won't change.
+    nsCOMPtr<nsIScreen> screen;
+    FindScreen (getter_AddRefs(screen));
+    if (screen) {
+        int32_t x, y, width, height;
+        screen->GetAvailRect(&x, &y, &width, &height);
+
+        // convert to device units
+        outRect->y = NSIntPixelsToAppUnits(y, AppUnitsPerDevPixel());
+        outRect->x = NSIntPixelsToAppUnits(x, AppUnitsPerDevPixel());
+        outRect->width = NSIntPixelsToAppUnits(width, AppUnitsPerDevPixel());
+        outRect->height = NSIntPixelsToAppUnits(height, AppUnitsPerDevPixel());
+    }
+}
+
+void
+nsDeviceContext::ComputeFullAreaUsingScreen(nsRect* outRect)
+{
+    // if we have more than one screen, we always need to recompute the clientRect
+    // because the window may have moved onto a different screen. In the single
+    // monitor case, we only need to do the computation if we haven't done it
+    // once already, and remember that we have because we're assured it won't change.
+    nsCOMPtr<nsIScreen> screen;
+    FindScreen ( getter_AddRefs(screen) );
+    if ( screen ) {
+        int32_t x, y, width, height;
+        screen->GetRect ( &x, &y, &width, &height );
+
+        // convert to device units
+        outRect->y = NSIntPixelsToAppUnits(y, AppUnitsPerDevPixel());
+        outRect->x = NSIntPixelsToAppUnits(x, AppUnitsPerDevPixel());
+        outRect->width = NSIntPixelsToAppUnits(width, AppUnitsPerDevPixel());
+        outRect->height = NSIntPixelsToAppUnits(height, AppUnitsPerDevPixel());
+
+        mWidth = outRect->width;
+        mHeight = outRect->height;
+    }
+}
+
+//
+// FindScreen
+//
+// Determines which screen intersects the largest area of the given surface.
+//
+void
+nsDeviceContext::FindScreen(nsIScreen** outScreen)
+{
+    if (!mWidget || !mScreenManager) {
+        return;
+    }
+
+    CheckDPIChange();
+
+    if (mWidget->GetOwningTabChild()) {
+        mScreenManager->ScreenForNativeWidget((void *)mWidget->GetOwningTabChild(),
+                                              outScreen);
+    }
+    else if (mWidget->GetNativeData(NS_NATIVE_WINDOW)) {
+        mScreenManager->ScreenForNativeWidget(mWidget->GetNativeData(NS_NATIVE_WINDOW),
+                                              outScreen);
+    }
+
+#ifdef MOZ_WIDGET_ANDROID
+    if (!(*outScreen)) {
+        nsCOMPtr<nsIScreen> screen = mWidget->GetWidgetScreen();
+        screen.forget(outScreen);
+    }
+#endif
+
+    if (!(*outScreen)) {
+        mScreenManager->GetPrimaryScreen(outScreen);
+    }
+}
+
+bool
+nsDeviceContext::CalcPrintingSize()
+{
+    if (!mPrintTarget) {
+        return (mWidth > 0 && mHeight > 0);
+    }
+
+    gfxSize size = mPrintTarget->GetSize();
+    // For printing, CSS inches and physical inches are identical
+    // so it doesn't matter which we use here
+    mWidth = NSToCoordRound(size.width * AppUnitsPerPhysicalInch()
+                            / POINTS_PER_INCH_FLOAT);
+    mHeight = NSToCoordRound(size.height * AppUnitsPerPhysicalInch()
+                             / POINTS_PER_INCH_FLOAT);
+
+    return (mWidth > 0 && mHeight > 0);
+}
+
+bool nsDeviceContext::CheckDPIChange(double* aScale)
+{
+    int32_t oldDevPixels = mAppUnitsPerDevPixelAtUnitFullZoom;
+    int32_t oldInches = mAppUnitsPerPhysicalInch;
+
+    SetDPI(aScale);
+
+    return oldDevPixels != mAppUnitsPerDevPixelAtUnitFullZoom ||
+        oldInches != mAppUnitsPerPhysicalInch;
+}
+
+bool
+nsDeviceContext::SetFullZoom(float aScale)
+{
+    if (aScale <= 0) {
+        NS_NOTREACHED("Invalid full zoom value");
+        return false;
+    }
+    int32_t oldAppUnitsPerDevPixel = mAppUnitsPerDevPixel;
+    mFullZoom = aScale;
+    UpdateAppUnitsForFullZoom();
+    return oldAppUnitsPerDevPixel != mAppUnitsPerDevPixel;
+}
+
+void
+nsDeviceContext::UpdateAppUnitsForFullZoom()
+{
+    mAppUnitsPerDevPixel =
+        std::max(1, NSToIntRound(float(mAppUnitsPerDevPixelAtUnitFullZoom) / mFullZoom));
+    // adjust mFullZoom to reflect appunit rounding
+    mFullZoom = float(mAppUnitsPerDevPixelAtUnitFullZoom) / mAppUnitsPerDevPixel;
+}
+
+DesktopToLayoutDeviceScale
+nsDeviceContext::GetDesktopToDeviceScale()
+{
+    nsCOMPtr<nsIScreen> screen;
+    FindScreen(getter_AddRefs(screen));
+
+    if (screen) {
+        double scale;
+        screen->GetContentsScaleFactor(&scale);
+        return DesktopToLayoutDeviceScale(scale);
+    }
+
+    return DesktopToLayoutDeviceScale(1.0);
+}
diff --git a/gfx/src/nsDeviceContext.h b/gfx/src/nsDeviceContext.h
new file mode 100644
index 000000000..1115757eb
--- /dev/null
+++ b/gfx/src/nsDeviceContext.h
@@ -0,0 +1,311 @@
+/* -*- Mode: C++; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef _NS_DEVICECONTEXT_H_
+#define _NS_DEVICECONTEXT_H_
+
+#include <stdint.h>                     // for uint32_t
+#include <sys/types.h>                  // for int32_t
+#include "gfxTypes.h"                   // for gfxFloat
+#include "gfxFont.h"                    // for gfxFont::Orientation
+#include "mozilla/Assertions.h"         // for MOZ_ASSERT_HELPER2
+#include "mozilla/RefPtr.h"             // for RefPtr
+#include "nsCOMPtr.h"                   // for nsCOMPtr
+#include "nsCoord.h"                    // for nscoord
+#include "nsError.h"                    // for nsresult
+#include "nsISupports.h"                // for NS_INLINE_DECL_REFCOUNTING
+#include "nsMathUtils.h"                // for NS_round
+#include "nscore.h"                     // for char16_t, nsAString
+#include "mozilla/AppUnits.h"           // for AppUnits
+#include "nsFontMetrics.h"              // for nsFontMetrics::Params
+
+class gfxContext;
+class gfxTextPerfMetrics;
+class gfxUserFontSet;
+struct nsFont;
+class nsFontCache;
+class nsIAtom;
+class nsIDeviceContextSpec;
+class nsIScreen;
+class nsIScreenManager;
+class nsIWidget;
+struct nsRect;
+
+namespace mozilla {
+namespace gfx {
+class PrintTarget;
+}
+}
+
+class nsDeviceContext final
+{
+public:
+    typedef mozilla::gfx::PrintTarget PrintTarget;
+
+    nsDeviceContext();
+
+    NS_INLINE_DECL_REFCOUNTING(nsDeviceContext)
+
+    /**
+     * Initialize the device context from a widget
+     * @param aWidget a widget to initialize the device context from
+     * @return error status
+     */
+    nsresult Init(nsIWidget *aWidget);
+
+    /**
+     * Initialize the device context from a device context spec
+     * @param aDevSpec the specification of the printing device
+     * @return error status
+     */
+    nsresult InitForPrinting(nsIDeviceContextSpec *aDevSpec);
+
+    /**
+     * Create a rendering context and initialize it.  Only call this
+     * method on device contexts that were initialized for printing.
+     *
+     * @return the new rendering context (guaranteed to be non-null)
+     */
+    already_AddRefed<gfxContext> CreateRenderingContext();
+
+    /**
+     * Create a reference rendering context and initialize it.  Only call this
+     * method on device contexts that were initialized for printing.
+     *
+     * @return the new rendering context.
+     */
+    already_AddRefed<gfxContext> CreateReferenceRenderingContext();
+
+    /**
+     * Gets the number of app units in one CSS pixel; this number is global,
+     * not unique to each device context.
+     */
+    static int32_t AppUnitsPerCSSPixel() { return mozilla::AppUnitsPerCSSPixel(); }
+
+    /**
+     * Gets the number of app units in one device pixel; this number
+     * is usually a factor of AppUnitsPerCSSPixel(), although that is
+     * not guaranteed.
+     */
+    int32_t AppUnitsPerDevPixel() const { return mAppUnitsPerDevPixel; }
+
+    /**
+     * Convert device pixels which is used for gfx/thebes to nearest
+     * (rounded) app units
+     */
+    nscoord GfxUnitsToAppUnits(gfxFloat aGfxUnits) const
+    { return nscoord(NS_round(aGfxUnits * AppUnitsPerDevPixel())); }
+
+    /**
+     * Convert app units to device pixels which is used for gfx/thebes.
+     */
+    gfxFloat AppUnitsToGfxUnits(nscoord aAppUnits) const
+    { return gfxFloat(aAppUnits) / AppUnitsPerDevPixel(); }
+
+    /**
+     * Gets the number of app units in one physical inch; this is the
+     * device's DPI times AppUnitsPerDevPixel().
+     */
+    int32_t AppUnitsPerPhysicalInch() const
+    { return mAppUnitsPerPhysicalInch; }
+
+    /**
+     * Gets the number of app units in one CSS inch; this is
+     * 96 times AppUnitsPerCSSPixel.
+     */
+    static int32_t AppUnitsPerCSSInch() { return mozilla::AppUnitsPerCSSInch(); }
+
+    /**
+     * Get the ratio of app units to dev pixels that would be used at unit
+     * (100%) full zoom.
+     */
+    int32_t AppUnitsPerDevPixelAtUnitFullZoom() const
+    { return mAppUnitsPerDevPixelAtUnitFullZoom; }
+
+    /**
+     * Get the nsFontMetrics that describe the properties of
+     * an nsFont.
+     * @param aFont font description to obtain metrics for
+     */
+    already_AddRefed<nsFontMetrics> GetMetricsFor(
+        const nsFont& aFont, const nsFontMetrics::Params& aParams);
+
+    /**
+     * Notification when a font metrics instance created for this device is
+     * about to be deleted
+     */
+    nsresult FontMetricsDeleted(const nsFontMetrics* aFontMetrics);
+
+    /**
+     * Attempt to free up resources by flushing out any fonts no longer
+     * referenced by anything other than the font cache itself.
+     * @return error status
+     */
+    nsresult FlushFontCache();
+
+    /**
+     * Return the bit depth of the device.
+     */
+    nsresult GetDepth(uint32_t& aDepth);
+
+    /**
+     * Get the size of the displayable area of the output device
+     * in app units.
+     * @param aWidth out parameter for width
+     * @param aHeight out parameter for height
+     * @return error status
+     */
+    nsresult GetDeviceSurfaceDimensions(nscoord& aWidth, nscoord& aHeight);
+
+    /**
+     * Get the size of the content area of the output device in app
+     * units.  This corresponds on a screen device, for instance, to
+     * the entire screen.
+     * @param aRect out parameter for full rect. Position (x,y) will
+     *              be (0,0) or relative to the primary monitor if
+     *              this is not the primary.
+     * @return error status
+     */
+    nsresult GetRect(nsRect& aRect);
+
+    /**
+     * Get the size of the content area of the output device in app
+     * units.  This corresponds on a screen device, for instance, to
+     * the area reported by GetDeviceSurfaceDimensions, minus the
+     * taskbar (Windows) or menubar (Macintosh).
+     * @param aRect out parameter for client rect. Position (x,y) will
+     *              be (0,0) adjusted for any upper/left non-client
+     *              space if present or relative to the primary
+     *              monitor if this is not the primary.
+     * @return error status
+     */
+    nsresult GetClientRect(nsRect& aRect);
+
+    /**
+     * Inform the output device that output of a document is beginning
+     * Used for print related device contexts. Must be matched 1:1 with
+     * EndDocument() or AbortDocument().
+     *
+     * @param aTitle - title of Document
+     * @param aPrintToFileName - name of file to print to, if empty then don't
+     *                           print to file
+     * @param aStartPage - starting page number (must be greater than zero)
+     * @param aEndPage - ending page number (must be less than or
+     * equal to number of pages)
+     *
+     * @return error status
+     */
+    nsresult BeginDocument(const nsAString& aTitle,
+                           const nsAString& aPrintToFileName,
+                           int32_t          aStartPage,
+                           int32_t          aEndPage);
+
+    /**
+     * Inform the output device that output of a document is ending.
+     * Used for print related device contexts. Must be matched 1:1 with
+     * BeginDocument()
+     * @return error status
+     */
+    nsresult EndDocument();
+
+    /**
+     * Inform the output device that output of a document is being aborted.
+     * Must be matched 1:1 with BeginDocument()
+     * @return error status
+     */
+    nsresult AbortDocument();
+
+    /**
+     * Inform the output device that output of a page is beginning
+     * Used for print related device contexts. Must be matched 1:1 with
+     * EndPage() and within a BeginDocument()/EndDocument() pair.
+     * @return error status
+     */
+    nsresult BeginPage();
+
+    /**
+     * Inform the output device that output of a page is ending
+     * Used for print related device contexts. Must be matched 1:1 with
+     * BeginPage() and within a BeginDocument()/EndDocument() pair.
+     * @return error status
+     */
+    nsresult EndPage();
+
+    /**
+     * Check to see if the DPI has changed, or impose a new DPI scale value.
+     * @param  aScale - If non-null, the default (unzoomed) CSS to device pixel
+     *                  scale factor will be returned here; and if it is > 0.0
+     *                  on input, the given value will be used instead of
+     *                  getting it from the widget (if any). This is used to
+     *                  allow subdocument contexts to inherit the resolution
+     *                  setting of their parent.
+     * @return whether there was actually a change in the DPI (whether
+     *         AppUnitsPerDevPixel() or AppUnitsPerPhysicalInch()
+     *         changed)
+     */
+    bool CheckDPIChange(double* aScale = nullptr);
+
+    /**
+     * Set the full zoom factor: all lengths are multiplied by this factor
+     * when we convert them to device pixels. Returns whether the ratio of
+     * app units to dev pixels changed because of the zoom factor.
+     */
+    bool SetFullZoom(float aScale);
+
+    /**
+     * Returns the page full zoom factor applied.
+     */
+    float GetFullZoom() const { return mFullZoom; }
+
+    /**
+     * True if this device context was created for printing.
+     */
+    bool IsPrinterContext();
+
+    mozilla::DesktopToLayoutDeviceScale GetDesktopToDeviceScale();
+
+private:
+    // Private destructor, to discourage deletion outside of Release():
+    ~nsDeviceContext();
+
+    /**
+     * Implementation shared by CreateRenderingContext and
+     * CreateReferenceRenderingContext.
+     */
+    already_AddRefed<gfxContext>
+    CreateRenderingContextCommon(bool aWantReferenceContext);
+
+    void SetDPI(double* aScale = nullptr);
+    void ComputeClientRectUsingScreen(nsRect *outRect);
+    void ComputeFullAreaUsingScreen(nsRect *outRect);
+    void FindScreen(nsIScreen **outScreen);
+
+    // Return false if the surface is not right
+    bool CalcPrintingSize();
+    void UpdateAppUnitsForFullZoom();
+
+    nscoord  mWidth;
+    nscoord  mHeight;
+    uint32_t mDepth;
+    int32_t  mAppUnitsPerDevPixel;
+    int32_t  mAppUnitsPerDevPixelAtUnitFullZoom;
+    int32_t  mAppUnitsPerPhysicalInch;
+    float    mFullZoom;
+    float    mPrintingScale;
+
+    RefPtr<nsFontCache>            mFontCache;
+    nsCOMPtr<nsIWidget>            mWidget;
+    nsCOMPtr<nsIScreenManager>     mScreenManager;
+    nsCOMPtr<nsIDeviceContextSpec> mDeviceContextSpec;
+    RefPtr<PrintTarget>            mPrintTarget;
+#ifdef XP_MACOSX
+    RefPtr<PrintTarget>            mCachedPrintTarget;
+#endif
+#ifdef DEBUG
+    bool mIsInitialized;
+#endif
+};
+
+#endif /* _NS_DEVICECONTEXT_H_ */
diff --git a/gfx/src/nsFont.cpp b/gfx/src/nsFont.cpp
new file mode 100644
index 000000000..c5b1f09f0
--- /dev/null
+++ b/gfx/src/nsFont.cpp
@@ -0,0 +1,297 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsFont.h"
+#include "gfxFont.h"                    // for gfxFontStyle
+#include "gfxFontConstants.h"           // for NS_FONT_KERNING_AUTO, etc
+#include "gfxFontFeatures.h"            // for gfxFontFeature, etc
+#include "gfxFontUtils.h"               // for TRUETYPE_TAG
+#include "nsCRT.h"                      // for nsCRT
+#include "nsDebug.h"                    // for NS_ASSERTION
+#include "nsISupports.h"
+#include "nsUnicharUtils.h"
+#include "nscore.h"                     // for char16_t
+#include "mozilla/ArrayUtils.h"
+#include "mozilla/gfx/2D.h"
+
+using namespace mozilla;
+
+nsFont::nsFont(const FontFamilyList& aFontlist, nscoord aSize)
+  : fontlist(aFontlist)
+{
+  Init();
+  size = aSize;
+}
+
+nsFont::nsFont(FontFamilyType aGenericType, nscoord aSize)
+  : fontlist(aGenericType)
+{
+  Init();
+  size = aSize;
+}
+
+void
+nsFont::Init()
+{
+  style = NS_FONT_STYLE_NORMAL;
+  weight = NS_FONT_WEIGHT_NORMAL;
+  stretch = NS_FONT_STRETCH_NORMAL;
+  systemFont = false;
+  smoothing = NS_FONT_SMOOTHING_AUTO;
+  sizeAdjust = -1.0f;
+  kerning = NS_FONT_KERNING_AUTO;
+  synthesis = NS_FONT_SYNTHESIS_WEIGHT | NS_FONT_SYNTHESIS_STYLE;
+
+  variantAlternates = 0;
+  variantCaps = NS_FONT_VARIANT_CAPS_NORMAL;
+  variantEastAsian = 0;
+  variantLigatures = 0;
+  variantNumeric = 0;
+  variantPosition = NS_FONT_VARIANT_POSITION_NORMAL;
+  variantWidth = NS_FONT_VARIANT_WIDTH_NORMAL;
+}
+
+nsFont::nsFont(const nsFont& aOther) = default;
+
+nsFont::nsFont()
+{
+}
+
+nsFont::~nsFont()
+{
+}
+
+bool nsFont::Equals(const nsFont& aOther) const
+{
+  if ((style == aOther.style) &&
+      (systemFont == aOther.systemFont) &&
+      (weight == aOther.weight) &&
+      (stretch == aOther.stretch) &&
+      (size == aOther.size) &&
+      (sizeAdjust == aOther.sizeAdjust) &&
+      (fontlist == aOther.fontlist) &&
+      (kerning == aOther.kerning) &&
+      (synthesis == aOther.synthesis) &&
+      (fontFeatureSettings == aOther.fontFeatureSettings) &&
+      (languageOverride == aOther.languageOverride) &&
+      (variantAlternates == aOther.variantAlternates) &&
+      (variantCaps == aOther.variantCaps) &&
+      (variantEastAsian == aOther.variantEastAsian) &&
+      (variantLigatures == aOther.variantLigatures) &&
+      (variantNumeric == aOther.variantNumeric) &&
+      (variantPosition == aOther.variantPosition) &&
+      (variantWidth == aOther.variantWidth) &&
+      (alternateValues == aOther.alternateValues) &&
+      (featureValueLookup == aOther.featureValueLookup) &&
+      (smoothing == aOther.smoothing)) {
+    return true;
+  }
+  return false;
+}
+
+nsFont& nsFont::operator=(const nsFont& aOther) = default;
+
+void
+nsFont::CopyAlternates(const nsFont& aOther)
+{
+  variantAlternates = aOther.variantAlternates;
+  alternateValues = aOther.alternateValues;
+  featureValueLookup = aOther.featureValueLookup;
+}
+
+// mapping from bitflag to font feature tag/value pair
+//
+// these need to be kept in sync with the constants listed
+// in gfxFontConstants.h (e.g. NS_FONT_VARIANT_EAST_ASIAN_JIS78)
+
+// NS_FONT_VARIANT_EAST_ASIAN_xxx values
+const gfxFontFeature eastAsianDefaults[] = {
+  { TRUETYPE_TAG('j','p','7','8'), 1 },
+  { TRUETYPE_TAG('j','p','8','3'), 1 },
+  { TRUETYPE_TAG('j','p','9','0'), 1 },
+  { TRUETYPE_TAG('j','p','0','4'), 1 },
+  { TRUETYPE_TAG('s','m','p','l'), 1 },
+  { TRUETYPE_TAG('t','r','a','d'), 1 },
+  { TRUETYPE_TAG('f','w','i','d'), 1 },
+  { TRUETYPE_TAG('p','w','i','d'), 1 },
+  { TRUETYPE_TAG('r','u','b','y'), 1 }
+};
+
+static_assert(MOZ_ARRAY_LENGTH(eastAsianDefaults) ==
+              eFeatureEastAsian_numFeatures,
+              "eFeatureEastAsian_numFeatures should be correct");
+
+// NS_FONT_VARIANT_LIGATURES_xxx values
+const gfxFontFeature ligDefaults[] = {
+  { TRUETYPE_TAG('l','i','g','a'), 0 },  // none value means all off
+  { TRUETYPE_TAG('l','i','g','a'), 1 },
+  { TRUETYPE_TAG('l','i','g','a'), 0 },
+  { TRUETYPE_TAG('d','l','i','g'), 1 },
+  { TRUETYPE_TAG('d','l','i','g'), 0 },
+  { TRUETYPE_TAG('h','l','i','g'), 1 },
+  { TRUETYPE_TAG('h','l','i','g'), 0 },
+  { TRUETYPE_TAG('c','a','l','t'), 1 },
+  { TRUETYPE_TAG('c','a','l','t'), 0 }
+};
+
+static_assert(MOZ_ARRAY_LENGTH(ligDefaults) ==
+              eFeatureLigatures_numFeatures,
+              "eFeatureLigatures_numFeatures should be correct");
+
+// NS_FONT_VARIANT_NUMERIC_xxx values
+const gfxFontFeature numericDefaults[] = {
+  { TRUETYPE_TAG('l','n','u','m'), 1 },
+  { TRUETYPE_TAG('o','n','u','m'), 1 },
+  { TRUETYPE_TAG('p','n','u','m'), 1 },
+  { TRUETYPE_TAG('t','n','u','m'), 1 },
+  { TRUETYPE_TAG('f','r','a','c'), 1 },
+  { TRUETYPE_TAG('a','f','r','c'), 1 },
+  { TRUETYPE_TAG('z','e','r','o'), 1 },
+  { TRUETYPE_TAG('o','r','d','n'), 1 }
+};
+
+static_assert(MOZ_ARRAY_LENGTH(numericDefaults) ==
+              eFeatureNumeric_numFeatures,
+              "eFeatureNumeric_numFeatures should be correct");
+
+static void
+AddFontFeaturesBitmask(uint32_t aValue, uint32_t aMin, uint32_t aMax,
+                      const gfxFontFeature aFeatureDefaults[],
+                      nsTArray<gfxFontFeature>& aFeaturesOut)
+
+{
+  uint32_t i, m;
+
+  for (i = 0, m = aMin; m <= aMax; i++, m <<= 1) {
+    if (m & aValue) {
+      const gfxFontFeature& feature = aFeatureDefaults[i];
+      aFeaturesOut.AppendElement(feature);
+    }
+  }
+}
+
+static uint32_t
+FontFeatureTagForVariantWidth(uint32_t aVariantWidth)
+{
+  switch (aVariantWidth) {
+    case NS_FONT_VARIANT_WIDTH_FULL:
+      return TRUETYPE_TAG('f','w','i','d');
+    case NS_FONT_VARIANT_WIDTH_HALF:
+      return TRUETYPE_TAG('h','w','i','d');
+    case NS_FONT_VARIANT_WIDTH_THIRD:
+      return TRUETYPE_TAG('t','w','i','d');
+    case NS_FONT_VARIANT_WIDTH_QUARTER:
+      return TRUETYPE_TAG('q','w','i','d');
+    default:
+      return 0;
+  }
+}
+
+void nsFont::AddFontFeaturesToStyle(gfxFontStyle *aStyle) const
+{
+  // add in font-variant features
+  gfxFontFeature setting;
+
+  // -- kerning
+  setting.mTag = TRUETYPE_TAG('k','e','r','n');
+  switch (kerning) {
+    case NS_FONT_KERNING_NONE:
+      setting.mValue = 0;
+      aStyle->featureSettings.AppendElement(setting);
+      break;
+    case NS_FONT_KERNING_NORMAL:
+      setting.mValue = 1;
+      aStyle->featureSettings.AppendElement(setting);
+      break;
+    default:
+      // auto case implies use user agent default
+      break;
+  }
+
+  // -- alternates
+  if (variantAlternates & NS_FONT_VARIANT_ALTERNATES_HISTORICAL) {
+    setting.mValue = 1;
+    setting.mTag = TRUETYPE_TAG('h','i','s','t');
+    aStyle->featureSettings.AppendElement(setting);
+  }
+
+  // -- copy font-specific alternate info into style
+  //    (this will be resolved after font-matching occurs)
+  aStyle->alternateValues.AppendElements(alternateValues);
+  aStyle->featureValueLookup = featureValueLookup;
+
+  // -- caps
+  aStyle->variantCaps = variantCaps;
+
+  // -- east-asian
+  if (variantEastAsian) {
+    AddFontFeaturesBitmask(variantEastAsian,
+                           NS_FONT_VARIANT_EAST_ASIAN_JIS78,
+                           NS_FONT_VARIANT_EAST_ASIAN_RUBY,
+                           eastAsianDefaults, aStyle->featureSettings);
+  }
+
+  // -- ligatures
+  if (variantLigatures) {
+    AddFontFeaturesBitmask(variantLigatures,
+                           NS_FONT_VARIANT_LIGATURES_NONE,
+                           NS_FONT_VARIANT_LIGATURES_NO_CONTEXTUAL,
+                           ligDefaults, aStyle->featureSettings);
+
+    if (variantLigatures & NS_FONT_VARIANT_LIGATURES_COMMON) {
+      // liga already enabled, need to enable clig also
+      setting.mTag = TRUETYPE_TAG('c','l','i','g');
+      setting.mValue = 1;
+      aStyle->featureSettings.AppendElement(setting);
+    } else if (variantLigatures & NS_FONT_VARIANT_LIGATURES_NO_COMMON) {
+      // liga already disabled, need to disable clig also
+      setting.mTag = TRUETYPE_TAG('c','l','i','g');
+      setting.mValue = 0;
+      aStyle->featureSettings.AppendElement(setting);
+    } else if (variantLigatures & NS_FONT_VARIANT_LIGATURES_NONE) {
+      // liga already disabled, need to disable dlig, hlig, calt, clig
+      setting.mValue = 0;
+      setting.mTag = TRUETYPE_TAG('d','l','i','g');
+      aStyle->featureSettings.AppendElement(setting);
+      setting.mTag = TRUETYPE_TAG('h','l','i','g');
+      aStyle->featureSettings.AppendElement(setting);
+      setting.mTag = TRUETYPE_TAG('c','a','l','t');
+      aStyle->featureSettings.AppendElement(setting);
+      setting.mTag = TRUETYPE_TAG('c','l','i','g');
+      aStyle->featureSettings.AppendElement(setting);
+    }
+  }
+
+  // -- numeric
+  if (variantNumeric) {
+    AddFontFeaturesBitmask(variantNumeric,
+                           NS_FONT_VARIANT_NUMERIC_LINING,
+                           NS_FONT_VARIANT_NUMERIC_ORDINAL,
+                           numericDefaults, aStyle->featureSettings);
+  }
+
+  // -- position
+  aStyle->variantSubSuper = variantPosition;
+
+  // -- width
+  setting.mTag = FontFeatureTagForVariantWidth(variantWidth);
+  if (setting.mTag) {
+    setting.mValue = 1;
+    aStyle->featureSettings.AppendElement(setting);
+  }
+
+  // indicate common-path case when neither variantCaps or variantSubSuper are set
+  aStyle->noFallbackVariantFeatures =
+    (aStyle->variantCaps == NS_FONT_VARIANT_CAPS_NORMAL) &&
+    (variantPosition == NS_FONT_VARIANT_POSITION_NORMAL);
+
+  // add in features from font-feature-settings
+  aStyle->featureSettings.AppendElements(fontFeatureSettings);
+
+  // enable grayscale antialiasing for text
+  if (smoothing == NS_FONT_SMOOTHING_GRAYSCALE) {
+    aStyle->useGrayscaleAntialiasing = true;
+  }
+}
diff --git a/gfx/src/nsFont.h b/gfx/src/nsFont.h
new file mode 100644
index 000000000..d21ce2593
--- /dev/null
+++ b/gfx/src/nsFont.h
@@ -0,0 +1,147 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsFont_h___
+#define nsFont_h___
+
+#include <stdint.h>                     // for uint8_t, uint16_t
+#include <sys/types.h>                  // for int16_t
+#include "gfxFontFamilyList.h"
+#include "gfxFontFeatures.h"
+#include "mozilla/RefPtr.h"             // for RefPtr
+#include "nsCoord.h"                    // for nscoord
+#include "nsStringFwd.h"                // for nsSubstring
+#include "nsString.h"               // for nsString
+#include "nsTArray.h"                   // for nsTArray
+
+struct gfxFontStyle;
+
+// XXX we need a method to enumerate all of the possible fonts on the
+// system across family, weight, style, size, etc. But not here!
+
+// Enumerator callback function. Return false to stop
+typedef bool (*nsFontFamilyEnumFunc)(const nsString& aFamily, bool aGeneric, void *aData);
+
+// IDs for generic fonts
+// NOTE: 0, 1 are reserved for the special IDs of the default variable
+// and fixed fonts in the presentation context, see nsPresContext.h
+const uint8_t kGenericFont_NONE         = 0x00;
+// Special
+const uint8_t kGenericFont_moz_variable = 0x00; // for the default variable width font
+const uint8_t kGenericFont_moz_fixed    = 0x01; // our special "use the user's fixed font"
+// CSS
+const uint8_t kGenericFont_serif        = 0x02;
+const uint8_t kGenericFont_sans_serif   = 0x04;
+const uint8_t kGenericFont_monospace    = 0x08;
+const uint8_t kGenericFont_cursive      = 0x10;
+const uint8_t kGenericFont_fantasy      = 0x20;
+
+// Font structure.
+struct nsFont {
+
+  // list of font families, either named or generic
+  mozilla::FontFamilyList fontlist;
+
+  // The style of font (normal, italic, oblique; see gfxFontConstants.h)
+  uint8_t style;
+
+  // Force this font to not be considered a 'generic' font, even if
+  // the name is the same as a CSS generic font family.
+  bool systemFont;
+
+  // Variant subproperties
+  uint8_t variantCaps;
+  uint8_t variantNumeric;
+  uint8_t variantPosition;
+  uint8_t variantWidth;
+
+  uint16_t variantLigatures;
+  uint16_t variantEastAsian;
+
+  // Some font-variant-alternates property values require
+  // font-specific settings defined via @font-feature-values rules.
+  // These are resolved *after* font matching occurs.
+
+  // -- bitmask for both enumerated and functional propvals
+  uint16_t variantAlternates;
+
+  // Smoothing - controls subpixel-antialiasing (currently OSX only)
+  uint8_t smoothing;
+
+  // The weight of the font; see gfxFontConstants.h.
+  uint16_t weight;
+
+  // The stretch of the font (the sum of various NS_FONT_STRETCH_*
+  // constants; see gfxFontConstants.h).
+  int16_t stretch;
+
+  // Kerning
+  uint8_t kerning;
+
+  // Synthesis setting, controls use of fake bolding/italics
+  uint8_t synthesis;
+
+  // The logical size of the font, in nscoord units
+  nscoord size;
+
+  // The aspect-value (ie., the ratio actualsize:actualxheight) that any
+  // actual physical font created from this font structure must have when
+  // rendering or measuring a string. A value of -1.0 means no adjustment
+  // needs to be done; otherwise the value must be nonnegative.
+  float sizeAdjust;
+
+  // -- list of value tags for font-specific alternate features
+  nsTArray<gfxAlternateValue> alternateValues;
+
+  // -- object used to look these up once the font is matched
+  RefPtr<gfxFontFeatureValueSet> featureValueLookup;
+
+  // Font features from CSS font-feature-settings
+  nsTArray<gfxFontFeature> fontFeatureSettings;
+
+  // Language system tag, to override document language;
+  // this is an OpenType "language system" tag represented as a 32-bit integer
+  // (see http://www.microsoft.com/typography/otspec/languagetags.htm).
+  nsString languageOverride;
+
+  // initialize the font with a fontlist
+  nsFont(const mozilla::FontFamilyList& aFontlist, nscoord aSize);
+
+  // initialize the font with a single generic
+  nsFont(mozilla::FontFamilyType aGenericType, nscoord aSize);
+
+  // Make a copy of the given font
+  nsFont(const nsFont& aFont);
+
+  // leave members uninitialized
+  nsFont();
+
+  ~nsFont();
+
+  bool operator==(const nsFont& aOther) const {
+    return Equals(aOther);
+  }
+
+  bool operator!=(const nsFont& aOther) const {
+    return !Equals(aOther);
+  }
+
+  bool Equals(const nsFont& aOther) const;
+
+  nsFont& operator=(const nsFont& aOther);
+
+  void CopyAlternates(const nsFont& aOther);
+
+  // Add featureSettings into style
+  void AddFontFeaturesToStyle(gfxFontStyle *aStyle) const;
+
+protected:
+  void Init(); // helper method for initialization
+};
+
+#define NS_FONT_VARIANT_NORMAL            0
+#define NS_FONT_VARIANT_SMALL_CAPS        1
+
+#endif /* nsFont_h___ */
diff --git a/gfx/src/nsFontMetrics.cpp b/gfx/src/nsFontMetrics.cpp
new file mode 100644
index 000000000..062bc73a2
--- /dev/null
+++ b/gfx/src/nsFontMetrics.cpp
@@ -0,0 +1,445 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsFontMetrics.h"
+#include <math.h>                       // for floor, ceil
+#include <algorithm>                    // for max
+#include "gfxFontConstants.h"           // for NS_FONT_SYNTHESIS_*
+#include "gfxPlatform.h"                // for gfxPlatform
+#include "gfxPoint.h"                   // for gfxPoint
+#include "gfxRect.h"                    // for gfxRect
+#include "gfxTypes.h"                   // for gfxFloat
+#include "nsBoundingMetrics.h"          // for nsBoundingMetrics
+#include "nsDebug.h"                    // for NS_ERROR
+#include "nsDeviceContext.h"            // for nsDeviceContext
+#include "nsIAtom.h"                    // for nsIAtom
+#include "nsMathUtils.h"                // for NS_round
+#include "nsRenderingContext.h"         // for nsRenderingContext
+#include "nsString.h"                   // for nsString
+#include "nsStyleConsts.h"              // for NS_STYLE_HYPHENS_NONE
+#include "mozilla/Assertions.h"         // for MOZ_ASSERT
+#include "mozilla/UniquePtr.h"          // for UniquePtr
+
+class gfxUserFontSet;
+using namespace mozilla;
+
+namespace {
+
+class AutoTextRun {
+public:
+    typedef mozilla::gfx::DrawTarget DrawTarget;
+
+    AutoTextRun(nsFontMetrics* aMetrics, DrawTarget* aDrawTarget,
+                const char* aString, int32_t aLength)
+    {
+        mTextRun = aMetrics->GetThebesFontGroup()->MakeTextRun(
+            reinterpret_cast<const uint8_t*>(aString), aLength,
+            aDrawTarget,
+            aMetrics->AppUnitsPerDevPixel(),
+            ComputeFlags(aMetrics),
+            nullptr);
+    }
+
+    AutoTextRun(nsFontMetrics* aMetrics, DrawTarget* aDrawTarget,
+                const char16_t* aString, int32_t aLength)
+    {
+        mTextRun = aMetrics->GetThebesFontGroup()->MakeTextRun(
+            aString, aLength,
+            aDrawTarget,
+            aMetrics->AppUnitsPerDevPixel(),
+            ComputeFlags(aMetrics),
+            nullptr);
+    }
+
+    gfxTextRun *get() { return mTextRun.get(); }
+    gfxTextRun *operator->() { return mTextRun.get(); }
+
+private:
+    static uint32_t ComputeFlags(nsFontMetrics* aMetrics) {
+        uint32_t flags = 0;
+        if (aMetrics->GetTextRunRTL()) {
+            flags |= gfxTextRunFactory::TEXT_IS_RTL;
+        }
+        if (aMetrics->GetVertical()) {
+            switch (aMetrics->GetTextOrientation()) {
+            case NS_STYLE_TEXT_ORIENTATION_MIXED:
+                flags |= gfxTextRunFactory::TEXT_ORIENT_VERTICAL_MIXED;
+                break;
+            case NS_STYLE_TEXT_ORIENTATION_UPRIGHT:
+                flags |= gfxTextRunFactory::TEXT_ORIENT_VERTICAL_UPRIGHT;
+                break;
+            case NS_STYLE_TEXT_ORIENTATION_SIDEWAYS:
+                flags |= gfxTextRunFactory::TEXT_ORIENT_VERTICAL_SIDEWAYS_RIGHT;
+                break;
+            }
+        }
+        return flags;
+    }
+
+    RefPtr<gfxTextRun> mTextRun;
+};
+
+class StubPropertyProvider : public gfxTextRun::PropertyProvider {
+public:
+    virtual void GetHyphenationBreaks(gfxTextRun::Range aRange,
+                                      bool* aBreakBefore) {
+        NS_ERROR("This shouldn't be called because we never call BreakAndMeasureText");
+    }
+    virtual int8_t GetHyphensOption() {
+        NS_ERROR("This shouldn't be called because we never call BreakAndMeasureText");
+        return NS_STYLE_HYPHENS_NONE;
+    }
+    virtual gfxFloat GetHyphenWidth() {
+        NS_ERROR("This shouldn't be called because we never enable hyphens");
+        return 0;
+    }
+    virtual already_AddRefed<mozilla::gfx::DrawTarget> GetDrawTarget() {
+        NS_ERROR("This shouldn't be called because we never enable hyphens");
+        return nullptr;
+    }
+    virtual uint32_t GetAppUnitsPerDevUnit() {
+        NS_ERROR("This shouldn't be called because we never enable hyphens");
+        return 60;
+    }
+    virtual void GetSpacing(gfxTextRun::Range aRange, Spacing* aSpacing) {
+        NS_ERROR("This shouldn't be called because we never enable spacing");
+    }
+};
+
+} // namespace
+
+nsFontMetrics::nsFontMetrics(const nsFont& aFont, const Params& aParams,
+                             nsDeviceContext *aContext)
+    : mFont(aFont)
+    , mLanguage(aParams.language)
+    , mDeviceContext(aContext)
+    , mP2A(aContext->AppUnitsPerDevPixel())
+    , mOrientation(aParams.orientation)
+    , mTextRunRTL(false)
+    , mVertical(false)
+    , mTextOrientation(0)
+{
+    gfxFontStyle style(aFont.style,
+                       aFont.weight,
+                       aFont.stretch,
+                       gfxFloat(aFont.size) / mP2A,
+                       aParams.language,
+                       aParams.explicitLanguage,
+                       aFont.sizeAdjust,
+                       aFont.systemFont,
+                       mDeviceContext->IsPrinterContext(),
+                       aFont.synthesis & NS_FONT_SYNTHESIS_WEIGHT,
+                       aFont.synthesis & NS_FONT_SYNTHESIS_STYLE,
+                       aFont.languageOverride);
+
+    aFont.AddFontFeaturesToStyle(&style);
+
+    gfxFloat devToCssSize = gfxFloat(mP2A) /
+        gfxFloat(mDeviceContext->AppUnitsPerCSSPixel());
+    mFontGroup = gfxPlatform::GetPlatform()->
+        CreateFontGroup(aFont.fontlist, &style, aParams.textPerf,
+                        aParams.userFontSet, devToCssSize);
+}
+
+nsFontMetrics::~nsFontMetrics()
+{
+    if (mDeviceContext) {
+        mDeviceContext->FontMetricsDeleted(this);
+    }
+}
+
+void
+nsFontMetrics::Destroy()
+{
+    mDeviceContext = nullptr;
+}
+
+// XXXTODO get rid of this macro
+#define ROUND_TO_TWIPS(x) (nscoord)floor(((x) * mP2A) + 0.5)
+#define CEIL_TO_TWIPS(x) (nscoord)ceil((x) * mP2A)
+
+const gfxFont::Metrics&
+nsFontMetrics::GetMetrics(gfxFont::Orientation aOrientation) const
+{
+    return mFontGroup->GetFirstValidFont()->GetMetrics(aOrientation);
+}
+
+nscoord
+nsFontMetrics::XHeight()
+{
+    return ROUND_TO_TWIPS(GetMetrics().xHeight);
+}
+
+nscoord
+nsFontMetrics::CapHeight()
+{
+    return ROUND_TO_TWIPS(GetMetrics().capHeight);
+}
+
+nscoord
+nsFontMetrics::SuperscriptOffset()
+{
+    return ROUND_TO_TWIPS(GetMetrics().emHeight *
+                          NS_FONT_SUPERSCRIPT_OFFSET_RATIO);
+}
+
+nscoord
+nsFontMetrics::SubscriptOffset()
+{
+    return ROUND_TO_TWIPS(GetMetrics().emHeight *
+                          NS_FONT_SUBSCRIPT_OFFSET_RATIO);
+}
+
+void
+nsFontMetrics::GetStrikeout(nscoord& aOffset, nscoord& aSize)
+{
+    aOffset = ROUND_TO_TWIPS(GetMetrics().strikeoutOffset);
+    aSize = ROUND_TO_TWIPS(GetMetrics().strikeoutSize);
+}
+
+void
+nsFontMetrics::GetUnderline(nscoord& aOffset, nscoord& aSize)
+{
+    aOffset = ROUND_TO_TWIPS(mFontGroup->GetUnderlineOffset());
+    aSize = ROUND_TO_TWIPS(GetMetrics().underlineSize);
+}
+
+// GetMaxAscent/GetMaxDescent/GetMaxHeight must contain the
+// text-decoration lines drawable area. See bug 421353.
+// BE CAREFUL for rounding each values. The logic MUST be same as
+// nsCSSRendering::GetTextDecorationRectInternal's.
+
+static gfxFloat ComputeMaxDescent(const gfxFont::Metrics& aMetrics,
+                                  gfxFontGroup* aFontGroup)
+{
+    gfxFloat offset = floor(-aFontGroup->GetUnderlineOffset() + 0.5);
+    gfxFloat size = NS_round(aMetrics.underlineSize);
+    gfxFloat minDescent = offset + size;
+    return floor(std::max(minDescent, aMetrics.maxDescent) + 0.5);
+}
+
+static gfxFloat ComputeMaxAscent(const gfxFont::Metrics& aMetrics)
+{
+    return floor(aMetrics.maxAscent + 0.5);
+}
+
+nscoord
+nsFontMetrics::InternalLeading()
+{
+    return ROUND_TO_TWIPS(GetMetrics().internalLeading);
+}
+
+nscoord
+nsFontMetrics::ExternalLeading()
+{
+    return ROUND_TO_TWIPS(GetMetrics().externalLeading);
+}
+
+nscoord
+nsFontMetrics::EmHeight()
+{
+    return ROUND_TO_TWIPS(GetMetrics().emHeight);
+}
+
+nscoord
+nsFontMetrics::EmAscent()
+{
+    return ROUND_TO_TWIPS(GetMetrics().emAscent);
+}
+
+nscoord
+nsFontMetrics::EmDescent()
+{
+    return ROUND_TO_TWIPS(GetMetrics().emDescent);
+}
+
+nscoord
+nsFontMetrics::MaxHeight()
+{
+    return CEIL_TO_TWIPS(ComputeMaxAscent(GetMetrics())) +
+        CEIL_TO_TWIPS(ComputeMaxDescent(GetMetrics(), mFontGroup));
+}
+
+nscoord
+nsFontMetrics::MaxAscent()
+{
+    return CEIL_TO_TWIPS(ComputeMaxAscent(GetMetrics()));
+}
+
+nscoord
+nsFontMetrics::MaxDescent()
+{
+    return CEIL_TO_TWIPS(ComputeMaxDescent(GetMetrics(), mFontGroup));
+}
+
+nscoord
+nsFontMetrics::MaxAdvance()
+{
+    return CEIL_TO_TWIPS(GetMetrics().maxAdvance);
+}
+
+nscoord
+nsFontMetrics::AveCharWidth()
+{
+    // Use CEIL instead of ROUND for consistency with GetMaxAdvance
+    return CEIL_TO_TWIPS(GetMetrics().aveCharWidth);
+}
+
+nscoord
+nsFontMetrics::SpaceWidth()
+{
+    // For vertical text with mixed or sideways orientation, we want the
+    // width of a horizontal space (even if we're using vertical line-spacing
+    // metrics, as with "writing-mode:vertical-*;text-orientation:mixed").
+    return CEIL_TO_TWIPS(
+        GetMetrics(mVertical &&
+                   mTextOrientation == NS_STYLE_TEXT_ORIENTATION_UPRIGHT
+                       ? gfxFont::eVertical
+                       : gfxFont::eHorizontal).spaceWidth);
+}
+
+int32_t
+nsFontMetrics::GetMaxStringLength()
+{
+    const gfxFont::Metrics& m = GetMetrics();
+    const double x = 32767.0 / m.maxAdvance;
+    int32_t len = (int32_t)floor(x);
+    return std::max(1, len);
+}
+
+nscoord
+nsFontMetrics::GetWidth(const char* aString, uint32_t aLength,
+                        DrawTarget* aDrawTarget)
+{
+    if (aLength == 0)
+        return 0;
+
+    if (aLength == 1 && aString[0] == ' ')
+        return SpaceWidth();
+
+    StubPropertyProvider provider;
+    AutoTextRun textRun(this, aDrawTarget, aString, aLength);
+    if (textRun.get()) {
+      return NSToCoordRound(
+          textRun->GetAdvanceWidth(Range(0, aLength), &provider));
+    }
+    return 0;
+}
+
+nscoord
+nsFontMetrics::GetWidth(const char16_t* aString, uint32_t aLength,
+                        DrawTarget* aDrawTarget)
+{
+    if (aLength == 0)
+        return 0;
+
+    if (aLength == 1 && aString[0] == ' ')
+        return SpaceWidth();
+
+    StubPropertyProvider provider;
+    AutoTextRun textRun(this, aDrawTarget, aString, aLength);
+    if (textRun.get()) {
+      return NSToCoordRound(
+          textRun->GetAdvanceWidth(Range(0, aLength), &provider));
+    }
+    return 0;
+}
+
+// Draw a string using this font handle on the surface passed in.
+void
+nsFontMetrics::DrawString(const char *aString, uint32_t aLength,
+                          nscoord aX, nscoord aY,
+                          nsRenderingContext *aContext)
+{
+    if (aLength == 0)
+        return;
+
+    StubPropertyProvider provider;
+    AutoTextRun textRun(this, aContext->GetDrawTarget(), aString, aLength);
+    if (!textRun.get()) {
+        return;
+    }
+    gfxPoint pt(aX, aY);
+    Range range(0, aLength);
+    if (mTextRunRTL) {
+        if (mVertical) {
+            pt.y += textRun->GetAdvanceWidth(range, &provider);
+        } else {
+            pt.x += textRun->GetAdvanceWidth(range, &provider);
+        }
+    }
+    gfxTextRun::DrawParams params(aContext->ThebesContext());
+    params.provider = &provider;
+    textRun->Draw(range, pt, params);
+}
+
+void
+nsFontMetrics::DrawString(const char16_t* aString, uint32_t aLength,
+                          nscoord aX, nscoord aY,
+                          nsRenderingContext *aContext,
+                          DrawTarget* aTextRunConstructionDrawTarget)
+{
+    if (aLength == 0)
+        return;
+
+    StubPropertyProvider provider;
+    AutoTextRun textRun(this, aTextRunConstructionDrawTarget, aString, aLength);
+    if (!textRun.get()) {
+        return;
+    }
+    gfxPoint pt(aX, aY);
+    Range range(0, aLength);
+    if (mTextRunRTL) {
+        if (mVertical) {
+            pt.y += textRun->GetAdvanceWidth(range, &provider);
+        } else {
+            pt.x += textRun->GetAdvanceWidth(range, &provider);
+        }
+    }
+    gfxTextRun::DrawParams params(aContext->ThebesContext());
+    params.provider = &provider;
+    textRun->Draw(range, pt, params);
+}
+
+static nsBoundingMetrics
+GetTextBoundingMetrics(nsFontMetrics* aMetrics, const char16_t* aString,
+                       uint32_t aLength, mozilla::gfx::DrawTarget* aDrawTarget,
+                       gfxFont::BoundingBoxType aType)
+{
+    if (aLength == 0)
+        return nsBoundingMetrics();
+
+    StubPropertyProvider provider;
+    AutoTextRun textRun(aMetrics, aDrawTarget, aString, aLength);
+    nsBoundingMetrics m;
+    if (textRun.get()) {
+        gfxTextRun::Metrics theMetrics = textRun->MeasureText(
+            gfxTextRun::Range(0, aLength), aType, aDrawTarget, &provider);
+
+        m.leftBearing  = NSToCoordFloor( theMetrics.mBoundingBox.X());
+        m.rightBearing = NSToCoordCeil(  theMetrics.mBoundingBox.XMost());
+        m.ascent       = NSToCoordCeil( -theMetrics.mBoundingBox.Y());
+        m.descent      = NSToCoordCeil(  theMetrics.mBoundingBox.YMost());
+        m.width        = NSToCoordRound( theMetrics.mAdvanceWidth);
+    }
+    return m;
+}
+
+nsBoundingMetrics
+nsFontMetrics::GetBoundingMetrics(const char16_t *aString, uint32_t aLength,
+                                  DrawTarget* aDrawTarget)
+{
+  return GetTextBoundingMetrics(this, aString, aLength, aDrawTarget,
+                                gfxFont::TIGHT_HINTED_OUTLINE_EXTENTS);
+}
+
+nsBoundingMetrics
+nsFontMetrics::GetInkBoundsForVisualOverflow(const char16_t *aString, uint32_t aLength,
+                                             DrawTarget* aDrawTarget)
+{
+  return GetTextBoundingMetrics(this, aString, aLength, aDrawTarget,
+                                gfxFont::LOOSE_INK_EXTENTS);
+}
+
diff --git a/gfx/src/nsFontMetrics.h b/gfx/src/nsFontMetrics.h
new file mode 100644
index 000000000..f8a2c5b93
--- /dev/null
+++ b/gfx/src/nsFontMetrics.h
@@ -0,0 +1,268 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef NSFONTMETRICS__H__
+#define NSFONTMETRICS__H__
+
+#include <stdint.h>                     // for uint32_t
+#include <sys/types.h>                  // for int32_t
+#include "gfxTextRun.h"                 // for gfxFont, gfxFontGroup
+#include "mozilla/Assertions.h"         // for MOZ_ASSERT_HELPER2
+#include "mozilla/RefPtr.h"             // for RefPtr
+#include "nsCOMPtr.h"                   // for nsCOMPtr
+#include "nsCoord.h"                    // for nscoord
+#include "nsError.h"                    // for nsresult
+#include "nsFont.h"                     // for nsFont
+#include "nsISupports.h"                // for NS_INLINE_DECL_REFCOUNTING
+#include "nscore.h"                     // for char16_t
+
+class gfxUserFontSet;
+class gfxTextPerfMetrics;
+class nsDeviceContext;
+class nsIAtom;
+class nsRenderingContext;
+struct nsBoundingMetrics;
+
+/**
+ * Font metrics
+ *
+ * This class may be somewhat misnamed. A better name might be
+ * nsFontList. The style system uses the nsFont struct for various
+ * font properties, one of which is font-family, which can contain a
+ * *list* of font names. The nsFont struct is "realized" by asking the
+ * device context to cough up an nsFontMetrics object, which contains
+ * a list of real font handles, one for each font mentioned in
+ * font-family (and for each fallback when we fall off the end of that
+ * list).
+ *
+ * The style system needs to have access to certain metrics, such as
+ * the em height (for the CSS "em" unit), and we use the first Western
+ * font's metrics for that purpose. The platform-specific
+ * implementations are expected to select non-Western fonts that "fit"
+ * reasonably well with the Western font that is loaded at Init time.
+ */
+class nsFontMetrics final
+{
+public:
+    typedef gfxTextRun::Range Range;
+    typedef mozilla::gfx::DrawTarget DrawTarget;
+
+    struct Params
+    {
+      nsIAtom* language = nullptr;
+      bool explicitLanguage = false;
+      gfxFont::Orientation orientation = gfxFont::eHorizontal;
+      gfxUserFontSet* userFontSet = nullptr;
+      gfxTextPerfMetrics* textPerf = nullptr;
+    };
+
+    nsFontMetrics(const nsFont& aFont, const Params& aParams,
+                  nsDeviceContext *aContext);
+
+    NS_INLINE_DECL_REFCOUNTING(nsFontMetrics)
+
+    /**
+     * Destroy this font metrics. This breaks the association between
+     * the font metrics and the device context.
+     */
+    void Destroy();
+
+    /**
+     * Return the font's x-height.
+     */
+    nscoord XHeight();
+
+    /**
+     * Return the font's cap-height.
+     */
+    nscoord CapHeight();
+
+    /**
+     * Return the font's superscript offset (the distance from the
+     * baseline to where a superscript's baseline should be placed).
+     * The value returned will be positive.
+     */
+    nscoord SuperscriptOffset();
+
+    /**
+     * Return the font's subscript offset (the distance from the
+     * baseline to where a subscript's baseline should be placed).
+     * The value returned will be positive.
+     */
+    nscoord SubscriptOffset();
+
+    /**
+     * Return the font's strikeout offset (the distance from the
+     * baseline to where a strikeout should be placed) and size.
+     * Positive values are above the baseline, negative below.
+     */
+    void GetStrikeout(nscoord& aOffset, nscoord& aSize);
+
+    /**
+     * Return the font's underline offset (the distance from the
+     * baseline to where a underline should be placed) and size.
+     * Positive values are above the baseline, negative below.
+     */
+    void GetUnderline(nscoord& aOffset, nscoord& aSize);
+
+    /**
+     * Returns the amount of internal leading for the font.
+     * This is normally the difference between the max ascent
+     * and the em ascent.
+     */
+    nscoord InternalLeading();
+
+    /**
+     * Returns the amount of external leading for the font.
+     * em ascent(?) plus external leading is the font designer's
+     * recommended line-height for this font.
+     */
+    nscoord ExternalLeading();
+
+    /**
+     * Returns the height of the em square.
+     * This is em ascent plus em descent.
+     */
+    nscoord EmHeight();
+
+    /**
+     * Returns the ascent part of the em square.
+     */
+    nscoord EmAscent();
+
+    /**
+     * Returns the descent part of the em square.
+     */
+    nscoord EmDescent();
+
+    /**
+     * Returns the height of the bounding box.
+     * This is max ascent plus max descent.
+     */
+    nscoord MaxHeight();
+
+    /**
+     * Returns the maximum distance characters in this font extend
+     * above the base line.
+     */
+    nscoord MaxAscent();
+
+    /**
+     * Returns the maximum distance characters in this font extend
+     * below the base line.
+     */
+    nscoord MaxDescent();
+
+    /**
+     * Returns the maximum character advance for the font.
+     */
+    nscoord MaxAdvance();
+
+    /**
+     * Returns the average character width
+     */
+    nscoord AveCharWidth();
+
+    /**
+     * Returns the often needed width of the space character
+     */
+    nscoord SpaceWidth();
+
+    /**
+     * Returns the font associated with these metrics. The return value
+     * is only defined after Init() has been called.
+     */
+    const nsFont &Font() const { return mFont; }
+
+    /**
+     * Returns the language associated with these metrics
+     */
+    nsIAtom* Language() const { return mLanguage; }
+
+    /**
+     * Returns the orientation (horizontal/vertical) of these metrics.
+     */
+    gfxFont::Orientation Orientation() const { return mOrientation; }
+
+    int32_t GetMaxStringLength();
+
+    // Get the width for this string.  aWidth will be updated with the
+    // width in points, not twips.  Callers must convert it if they
+    // want it in another format.
+    nscoord GetWidth(const char* aString, uint32_t aLength,
+                     DrawTarget* aDrawTarget);
+    nscoord GetWidth(const char16_t* aString, uint32_t aLength,
+                     DrawTarget* aDrawTarget);
+
+    // Draw a string using this font handle on the surface passed in.
+    void DrawString(const char *aString, uint32_t aLength,
+                    nscoord aX, nscoord aY,
+                    nsRenderingContext *aContext);
+    void DrawString(const char16_t* aString, uint32_t aLength,
+                    nscoord aX, nscoord aY,
+                    nsRenderingContext *aContext,
+                    DrawTarget* aTextRunConstructionDrawTarget);
+
+    nsBoundingMetrics GetBoundingMetrics(const char16_t *aString,
+                                         uint32_t aLength,
+                                         DrawTarget* aDrawTarget);
+
+    // Returns the LOOSE_INK_EXTENTS bounds of the text for determing the
+    // overflow area of the string.
+    nsBoundingMetrics GetInkBoundsForVisualOverflow(const char16_t *aString,
+                                                    uint32_t aLength,
+                                                    DrawTarget* aDrawTarget);
+
+    void SetTextRunRTL(bool aIsRTL) { mTextRunRTL = aIsRTL; }
+    bool GetTextRunRTL() const { return mTextRunRTL; }
+
+    void SetVertical(bool aVertical) { mVertical = aVertical; }
+    bool GetVertical() const { return mVertical; }
+
+    void SetTextOrientation(uint8_t aTextOrientation)
+    {
+      mTextOrientation = aTextOrientation;
+    }
+    uint8_t GetTextOrientation() const { return mTextOrientation; }
+
+    gfxFontGroup* GetThebesFontGroup() const { return mFontGroup; }
+    gfxUserFontSet* GetUserFontSet() const
+    {
+      return mFontGroup->GetUserFontSet();
+    }
+
+    int32_t AppUnitsPerDevPixel() const { return mP2A; }
+
+private:
+    // Private destructor, to discourage deletion outside of Release():
+    ~nsFontMetrics();
+
+    const gfxFont::Metrics& GetMetrics() const {
+      return GetMetrics(mOrientation);
+    }
+
+    const gfxFont::Metrics&
+    GetMetrics(const gfxFont::Orientation aFontOrientation) const;
+
+    nsFont mFont;
+    RefPtr<gfxFontGroup> mFontGroup;
+    nsCOMPtr<nsIAtom> mLanguage;
+    nsDeviceContext* mDeviceContext;
+    int32_t mP2A;
+
+    // The font orientation (horizontal or vertical) for which these metrics
+    // have been initialized. This determines which line metrics (ascent and
+    // descent) they will return.
+    gfxFont::Orientation mOrientation;
+
+    // These fields may be set by clients to control the behavior of methods
+    // like GetWidth and DrawString according to the writing mode, direction
+    // and text-orientation desired.
+    bool mTextRunRTL;
+    bool mVertical;
+    uint8_t mTextOrientation;
+};
+
+#endif /* NSFONTMETRICS__H__ */
diff --git a/gfx/src/nsGfxCIID.h b/gfx/src/nsGfxCIID.h
new file mode 100644
index 000000000..37cc27d0d
--- /dev/null
+++ b/gfx/src/nsGfxCIID.h
@@ -0,0 +1,21 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsGfxCIID_h__
+#define nsGfxCIID_h__
+
+#define NS_FONT_ENUMERATOR_CID \
+{ 0xa6cf9115, 0x15b3, 0x11d2, \
+{ 0x93, 0x2e, 0x00, 0x80, 0x5f, 0x8a, 0xdd, 0x32 } }
+
+#define NS_SCRIPTABLE_REGION_CID \
+{ 0xda5b130a, 0x1dd1, 0x11b2, \
+{ 0xad, 0x47, 0xf4, 0x55, 0xb1, 0x81, 0x4a, 0x78 } }
+
+#define NS_GFX_INITIALIZATION_CID \
+{ 0x67c41576, 0x9664, 0x4ed5, \
+{ 0x90, 0xc1, 0xf6, 0x68, 0x3f, 0xd5, 0x2c, 0x8f } }
+
+#endif
diff --git a/gfx/src/nsIFontEnumerator.idl b/gfx/src/nsIFontEnumerator.idl
new file mode 100644
index 000000000..f5f4c6468
--- /dev/null
+++ b/gfx/src/nsIFontEnumerator.idl
@@ -0,0 +1,61 @@
+/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+[scriptable, uuid(924d98d9-3518-4cb4-8708-c74fe8e3ec3c)]
+interface nsIFontEnumerator : nsISupports
+{
+  /**
+   * Return a sorted array of the names of all installed fonts.
+   *
+   * @param  aCount     returns number of names returned
+   * @param  aResult    returns array of names
+   * @return void
+   */
+  void EnumerateAllFonts(out uint32_t aCount,
+    [retval, array, size_is(aCount)] out wstring aResult);
+
+  /**
+   * Return a sorted array of names of fonts that support the given language
+   * group and are suitable for use as the given CSS generic font.
+   *
+   * @param  aLangGroup language group
+   * @param  aGeneric   CSS generic font
+   * @param  aCount     returns number of names returned
+   * @param  aResult    returns array of names
+   * @return void
+   */
+  void EnumerateFonts(in string aLangGroup, in string aGeneric,
+    out uint32_t aCount, [retval, array, size_is(aCount)] out wstring aResult);
+
+  /**
+    @param  aLangGroup language group
+    @return bool do we have a font for this language group
+   */
+  void HaveFontFor(in string aLangGroup, [retval] out boolean aResult);
+
+  /**
+   * @param  aLangGroup language group
+   * @param  aGeneric CSS generic font
+   * @return suggested default font for this language group and generic family
+   */
+  wstring getDefaultFont(in string aLangGroup, in string aGeneric);
+
+  /**
+   * update the global font list
+   * return true if font list is changed
+   */
+  boolean updateFontList();
+
+  /**
+   * get the standard family name on the system from given family
+   * @param  aName family name which may be alias
+   * @return the standard family name on the system, if given name does not
+   *         exist, returns empty string
+   */
+  wstring getStandardFamilyName(in wstring aName);
+};
diff --git a/gfx/src/nsIScriptableRegion.idl b/gfx/src/nsIScriptableRegion.idl
new file mode 100644
index 000000000..1e32fdd1b
--- /dev/null
+++ b/gfx/src/nsIScriptableRegion.idl
@@ -0,0 +1,176 @@
+/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+%{C++
+#include "nsRegionFwd.h"
+%}
+
+native nsIntRegion(nsIntRegion);
+
+
+[scriptable, uuid(a5f44cc7-2820-489b-b817-ae8a08506ff6)]
+interface nsIScriptableRegion : nsISupports
+{
+  void init ( ) ;
+
+  /**
+  * copy operator equivalent that takes another region
+  *
+  * @param      region to copy
+  * @return     void
+  *
+  **/
+
+  void setToRegion ( in nsIScriptableRegion aRegion );
+
+  /**
+  * copy operator equivalent that takes a rect
+  *
+  * @param      aX xoffset of rect to set region to
+  * @param      aY yoffset of rect to set region to
+  * @param      aWidth width of rect to set region to
+  * @param      aHeight height of rect to set region to
+  * @return     void
+  *
+  **/
+
+  void setToRect ( in long aX, in long aY, in long aWidth, in long aHeight );
+
+  /**
+  * destructively intersect another region with this one
+  *
+  * @param      region to intersect
+  * @return     void
+  *
+  **/
+
+  void intersectRegion ( in nsIScriptableRegion aRegion ) ;
+
+  /**
+  * destructively intersect a rect with this region
+  *
+  * @param      aX xoffset of rect to intersect with region
+  * @param      aY yoffset of rect to intersect with region
+  * @param      aWidth width of rect to intersect with region
+  * @param      aHeight height of rect to intersect with region
+  * @return     void
+  *
+  **/
+
+  void intersectRect ( in long aX, in long aY, in long aWidth, in long aHeight ) ;
+
+  /**
+  * destructively union another region with this one
+  *
+  * @param      region to union
+  * @return     void
+  *
+  **/
+
+  void unionRegion ( in nsIScriptableRegion aRegion ) ;
+
+  /**
+  * destructively union a rect with this region
+  *
+  * @param      aX xoffset of rect to union with region
+  * @param      aY yoffset of rect to union with region
+  * @param      aWidth width of rect to union with region
+  * @param      aHeight height of rect to union with region
+  * @return     void
+  *
+  **/
+
+  void unionRect ( in long aX, in long aY, in long aWidth, in long aHeight ) ;
+
+  /**
+  * destructively subtract another region with this one
+  *
+  * @param      region to subtract
+  * @return     void
+  *
+  **/
+
+  void subtractRegion ( in nsIScriptableRegion aRegion ) ;
+
+  /**
+  * destructively subtract a rect from this region
+  *
+  * @param      aX xoffset of rect to subtract with region
+  * @param      aY yoffset of rect to subtract with region
+  * @param      aWidth width of rect to subtract with region
+  * @param      aHeight height of rect to subtract with region
+  * @return     void
+  *
+  **/
+
+  void subtractRect ( in long aX, in long aY, in long aWidth, in long aHeight ) ;
+  
+  /**
+  * is this region empty? i.e. does it contain any pixels
+  *
+  * @param      none
+  * @return     returns whether the region is empty
+  *
+  **/
+
+  boolean isEmpty ( ) ;
+
+  /**
+  * == operator equivalent i.e. do the regions contain exactly
+  * the same pixels
+  *
+  * @param      region to compare
+  * @return     whether the regions are identical
+  *
+  **/
+
+  boolean isEqualRegion ( in nsIScriptableRegion aRegion ) ;
+
+  /**
+  * returns the bounding box of the region i.e. the smallest
+  * rectangle that completely contains the region.        
+  *
+  * @param      aX out parameter for xoffset of bounding rect for region
+  * @param      aY out parameter for yoffset of bounding rect for region
+  * @param      aWidth out parameter for width of bounding rect for region
+  * @param      aHeight out parameter for height of bounding rect for region
+  * @return     void
+  *
+  **/
+  void getBoundingBox ( out long aX, out long aY, out long aWidth, out long aHeight ) ;
+
+  /**
+  * offsets the region in x and y
+  *
+  * @param  xoffset  pixel offset in x
+  * @param  yoffset  pixel offset in y
+  * @return          void
+  *
+  **/
+  void offset ( in long aXOffset, in long aYOffset ) ;
+
+  /**
+   * @return null if there are no rects,
+   * @return flat array of rects,ie [x1,y1,width1,height1,x2...].
+   * The result will contain bogus data if values don't fit in 31 bit
+   **/
+  [implicit_jscontext] jsval getRects();
+
+  /**
+  * does the region intersect the rectangle?
+  *
+  * @param      rect to check for containment
+  * @return     true if the region intersects the rect
+  *
+  **/
+
+  boolean containsRect ( in long aX, in long aY, in long aWidth, in long aHeight ) ;
+  
+  [noscript] readonly attribute nsIntRegion region;
+  
+};
diff --git a/gfx/src/nsITheme.h b/gfx/src/nsITheme.h
new file mode 100644
index 000000000..9456a7394
--- /dev/null
+++ b/gfx/src/nsITheme.h
@@ -0,0 +1,206 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* service providing platform-specific native rendering for widgets */
+
+#ifndef nsITheme_h_
+#define nsITheme_h_
+
+#include "nsISupports.h"
+#include "nsCOMPtr.h"
+#include "nsColor.h"
+#include "Units.h"
+
+struct nsRect;
+class nsAttrValue;
+class nsPresContext;
+class nsRenderingContext;
+class nsDeviceContext;
+class nsIFrame;
+class nsIAtom;
+class nsIWidget;
+
+// IID for the nsITheme interface
+// {7329f760-08cb-450f-8225-dae729096dec}
+ #define NS_ITHEME_IID     \
+{ 0x7329f760, 0x08cb, 0x450f, \
+  { 0x82, 0x25, 0xda, 0xe7, 0x29, 0x09, 0x6d, 0xec } }
+// {0ae05515-cf7a-45a8-9e02-6556de7685b1}
+#define NS_THEMERENDERER_CID \
+{ 0x0ae05515, 0xcf7a, 0x45a8, \
+  { 0x9e, 0x02, 0x65, 0x56, 0xde, 0x76, 0x85, 0xb1 } }
+
+/**
+ * nsITheme is a service that provides platform-specific native
+ * rendering for widgets.  In other words, it provides the necessary
+ * operations to draw a rendering object (an nsIFrame) as a native
+ * widget.
+ *
+ * All the methods on nsITheme take a rendering context or device
+ * context, a frame (the rendering object), and a widget type (one of
+ * the constants in nsThemeConstants.h).
+ */
+class nsITheme: public nsISupports {
+public:
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_ITHEME_IID)
+
+  /**
+   * Draw the actual theme background.
+   * @param aContext the context to draw into
+   * @param aFrame the frame for the widget that we're drawing
+   * @param aWidgetType the -moz-appearance value to draw
+   * @param aRect the rectangle defining the area occupied by the widget
+   * @param aDirtyRect the rectangle that needs to be drawn
+   */
+  NS_IMETHOD DrawWidgetBackground(nsRenderingContext* aContext,
+                                  nsIFrame* aFrame,
+                                  uint8_t aWidgetType,
+                                  const nsRect& aRect,
+                                  const nsRect& aDirtyRect) = 0;
+
+  /**
+   * Get the computed CSS border for the widget, in pixels.
+   */
+  NS_IMETHOD GetWidgetBorder(nsDeviceContext* aContext, 
+                             nsIFrame* aFrame,
+                             uint8_t aWidgetType,
+                             nsIntMargin* aResult)=0;
+
+  /**
+   * This method can return false to indicate that the CSS padding
+   * value should be used.  Otherwise, it will fill in aResult with the
+   * computed padding, in pixels, and return true.
+   *
+   * XXXldb This ought to be required to return true for non-containers
+   * so that we don't let specified padding that has no effect change
+   * the computed padding and potentially the size.
+   */
+  virtual bool GetWidgetPadding(nsDeviceContext* aContext,
+                                  nsIFrame* aFrame,
+                                  uint8_t aWidgetType,
+                                  nsIntMargin* aResult) = 0;
+
+  /**
+   * On entry, *aResult is positioned at 0,0 and sized to the new size
+   * of aFrame (aFrame->GetSize() may be stale and should not be used).
+   * This method can return false to indicate that no special
+   * overflow area is required by the native widget. Otherwise it will
+   * fill in aResult with the desired overflow area, in appunits, relative
+   * to the frame origin, and return true.
+   *
+   * This overflow area is used to determine what area needs to be
+   * repainted when the widget changes.  However, it does not affect the
+   * widget's size or what area is reachable by scrollbars.  (In other
+   * words, in layout terms, it affects visual overflow but not
+   * scrollable overflow.)
+   */
+  virtual bool GetWidgetOverflow(nsDeviceContext* aContext,
+                                   nsIFrame* aFrame,
+                                   uint8_t aWidgetType,
+                                   /*INOUT*/ nsRect* aOverflowRect)
+  { return false; }
+
+  /**
+   * Get the minimum border-box size of a widget, in *pixels* (in
+   * |aResult|).  If |aIsOverridable| is set to true, this size is a
+   * minimum size; if false, this size is the only valid size for the
+   * widget.
+   */
+  NS_IMETHOD GetMinimumWidgetSize(nsPresContext* aPresContext,
+                                  nsIFrame* aFrame,
+                                  uint8_t aWidgetType,
+                                  mozilla::LayoutDeviceIntSize* aResult,
+                                  bool* aIsOverridable)=0;
+
+
+  enum Transparency {
+    eOpaque = 0,
+    eTransparent,
+    eUnknownTransparency
+  };
+
+  /**
+   * Returns what we know about the transparency of the widget.
+   */
+  virtual Transparency GetWidgetTransparency(nsIFrame* aFrame, uint8_t aWidgetType)
+  { return eUnknownTransparency; }
+
+  NS_IMETHOD WidgetStateChanged(nsIFrame* aFrame, uint8_t aWidgetType, 
+                                nsIAtom* aAttribute, bool* aShouldRepaint,
+                                const nsAttrValue* aOldValue)=0;
+
+  NS_IMETHOD ThemeChanged()=0;
+
+  virtual bool WidgetAppearanceDependsOnWindowFocus(uint8_t aWidgetType)
+  { return false; }
+
+  virtual bool NeedToClearBackgroundBehindWidget(nsIFrame* aFrame,
+                                                 uint8_t aWidgetType)
+  { return false; }
+
+  virtual bool WidgetProvidesFontSmoothingBackgroundColor(nsIFrame* aFrame,
+                                      uint8_t aWidgetType, nscolor* aColor)
+  { return false; }
+
+  /**
+   * ThemeGeometryType values are used for describing themed nsIFrames in
+   * calls to nsIWidget::UpdateThemeGeometries. We don't simply pass the
+   * -moz-appearance value ("widget type") of the frame because the widget may
+   * want to treat different frames with the same -moz-appearance differently
+   * based on other properties of the frame. So we give the theme a first look
+   * at the frame in nsITheme::ThemeGeometryTypeForWidget and pass the
+   * returned ThemeGeometryType along to the widget.
+   * Each theme backend defines the ThemeGeometryType values it needs in its
+   * own nsITheme subclass. eThemeGeometryTypeUnknown is the only value that's
+   * shared between backends.
+   */
+  typedef uint8_t ThemeGeometryType;
+  enum {
+    eThemeGeometryTypeUnknown = 0
+  };
+
+  /**
+   * Returns the theme geometry type that should be used in the ThemeGeometry
+   * array that's passed to the widget using nsIWidget::UpdateThemeGeometries.
+   * A return value of eThemeGeometryTypeUnknown means that this frame will
+   * not be included in the ThemeGeometry array.
+   */
+  virtual ThemeGeometryType ThemeGeometryTypeForWidget(nsIFrame* aFrame,
+                                                       uint8_t aWidgetType)
+  { return eThemeGeometryTypeUnknown; }
+
+  /**
+   * Can the nsITheme implementation handle this widget?
+   */
+  virtual bool ThemeSupportsWidget(nsPresContext* aPresContext,
+                                     nsIFrame* aFrame,
+                                     uint8_t aWidgetType)=0;
+
+  virtual bool WidgetIsContainer(uint8_t aWidgetType)=0;
+
+  /**
+   * Does the nsITheme implementation draw its own focus ring for this widget?
+   */
+  virtual bool ThemeDrawsFocusForWidget(uint8_t aWidgetType)=0;
+  
+  /**
+    * Should we insert a dropmarker inside of combobox button?
+   */
+  virtual bool ThemeNeedsComboboxDropmarker()=0;
+
+  /**
+   * Should we hide scrollbars?
+   */
+  virtual bool ShouldHideScrollbars()
+  { return false; }
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(nsITheme, NS_ITHEME_IID)
+
+// Creator function
+extern nsresult NS_NewNativeTheme(nsISupports *aOuter, REFNSIID aIID, void **aResult);
+
+#endif
diff --git a/gfx/src/nsMargin.h b/gfx/src/nsMargin.h
new file mode 100644
index 000000000..d9b0b8bd9
--- /dev/null
+++ b/gfx/src/nsMargin.h
@@ -0,0 +1,26 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef NSMARGIN_H
+#define NSMARGIN_H
+
+#include "nsCoord.h"
+#include "nsPoint.h"
+#include "mozilla/gfx/BaseMargin.h"
+#include "mozilla/gfx/Rect.h"
+
+struct nsMargin : public mozilla::gfx::BaseMargin<nscoord, nsMargin> {
+  typedef mozilla::gfx::BaseMargin<nscoord, nsMargin> Super;
+
+  // Constructors
+  nsMargin() : Super() {}
+  nsMargin(const nsMargin& aMargin) : Super(aMargin) {}
+  nsMargin(nscoord aTop, nscoord aRight, nscoord aBottom, nscoord aLeft)
+    : Super(aTop, aRight, aBottom, aLeft) {}
+};
+
+typedef mozilla::gfx::IntMargin nsIntMargin;
+
+#endif /* NSMARGIN_H */
diff --git a/gfx/src/nsPoint.h b/gfx/src/nsPoint.h
new file mode 100644
index 000000000..b377eb5a5
--- /dev/null
+++ b/gfx/src/nsPoint.h
@@ -0,0 +1,106 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef NSPOINT_H
+#define NSPOINT_H
+
+#include "nsCoord.h"
+#include "mozilla/gfx/BaseSize.h"
+#include "mozilla/gfx/BasePoint.h"
+#include "nsSize.h"
+#include "mozilla/gfx/Point.h"
+
+// nsIntPoint represents a point in one of the types of pixels.
+// Uses of nsIntPoint should eventually be converted to CSSIntPoint,
+// LayoutDeviceIntPoint, etc. (see layout/base/Units.h).
+typedef mozilla::gfx::IntPoint nsIntPoint;
+
+// nsPoint represents a point in app units.
+
+struct nsPoint : public mozilla::gfx::BasePoint<nscoord, nsPoint> {
+  typedef mozilla::gfx::BasePoint<nscoord, nsPoint> Super;
+
+  nsPoint() : Super() {}
+  nsPoint(const nsPoint& aPoint) : Super(aPoint) {}
+  nsPoint(nscoord aX, nscoord aY) : Super(aX, aY) {}
+
+  inline nsIntPoint ScaleToNearestPixels(float aXScale, float aYScale,
+                                         nscoord aAppUnitsPerPixel) const;
+  inline nsIntPoint ToNearestPixels(nscoord aAppUnitsPerPixel) const;
+
+  /**
+   * Return this point scaled to a different appunits per pixel (APP) ratio.
+   * @param aFromAPP the APP to scale from
+   * @param aToAPP the APP to scale to
+   */
+  MOZ_MUST_USE inline nsPoint
+    ScaleToOtherAppUnits(int32_t aFromAPP, int32_t aToAPP) const;
+
+  MOZ_MUST_USE inline nsPoint
+    RemoveResolution(const float resolution) const;
+  MOZ_MUST_USE inline nsPoint
+    ApplyResolution(const float resolution) const;
+};
+
+inline nsPoint ToAppUnits(const nsIntPoint& aPoint, nscoord aAppUnitsPerPixel);
+
+inline nsIntPoint
+nsPoint::ScaleToNearestPixels(float aXScale, float aYScale,
+                              nscoord aAppUnitsPerPixel) const
+{
+  return nsIntPoint(
+      NSToIntRoundUp(NSAppUnitsToDoublePixels(x, aAppUnitsPerPixel) * aXScale),
+      NSToIntRoundUp(NSAppUnitsToDoublePixels(y, aAppUnitsPerPixel) * aYScale));
+}
+
+inline nsIntPoint
+nsPoint::ToNearestPixels(nscoord aAppUnitsPerPixel) const
+{
+  return ScaleToNearestPixels(1.0f, 1.0f, aAppUnitsPerPixel);
+}
+
+inline nsPoint
+nsPoint::ScaleToOtherAppUnits(int32_t aFromAPP, int32_t aToAPP) const
+{
+  if (aFromAPP != aToAPP) {
+    nsPoint point;
+    point.x = NSToCoordRound(NSCoordScale(x, aFromAPP, aToAPP));
+    point.y = NSToCoordRound(NSCoordScale(y, aFromAPP, aToAPP));
+    return point;
+  }
+  return *this;
+}
+
+inline nsPoint
+nsPoint::RemoveResolution(const float resolution) const {
+  if (resolution != 1.0f) {
+    nsPoint point;
+    point.x = NSToCoordRound(NSCoordToFloat(x) / resolution);
+    point.y = NSToCoordRound(NSCoordToFloat(y) / resolution);
+    return point;
+  }
+  return *this;
+}
+
+inline nsPoint
+nsPoint::ApplyResolution(const float resolution) const {
+  if (resolution != 1.0f) {
+    nsPoint point;
+    point.x = NSToCoordRound(NSCoordToFloat(x) * resolution);
+    point.y = NSToCoordRound(NSCoordToFloat(y) * resolution);
+    return point;
+  }
+  return *this;
+}
+
+// app units are integer multiples of pixels, so no rounding needed
+inline nsPoint
+ToAppUnits(const nsIntPoint& aPoint, nscoord aAppUnitsPerPixel)
+{
+  return nsPoint(NSIntPixelsToAppUnits(aPoint.x, aAppUnitsPerPixel),
+                 NSIntPixelsToAppUnits(aPoint.y, aAppUnitsPerPixel));
+}
+
+#endif /* NSPOINT_H */
diff --git a/gfx/src/nsRect.cpp b/gfx/src/nsRect.cpp
new file mode 100644
index 000000000..c17c249b2
--- /dev/null
+++ b/gfx/src/nsRect.cpp
@@ -0,0 +1,62 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsRect.h"
+#include "mozilla/gfx/Types.h"          // for NS_SIDE_BOTTOM, etc
+#include "mozilla/CheckedInt.h"         // for CheckedInt
+#include "nsDeviceContext.h"            // for nsDeviceContext
+#include "nsString.h"               // for nsAutoString, etc
+#include "nsMargin.h"                   // for nsMargin
+
+static_assert((int(NS_SIDE_TOP) == 0) &&
+              (int(NS_SIDE_RIGHT) == 1) &&
+              (int(NS_SIDE_BOTTOM) == 2) &&
+              (int(NS_SIDE_LEFT) == 3),
+              "The mozilla::css::Side sequence must match the nsMargin nscoord sequence");
+
+const mozilla::gfx::IntRect& GetMaxSizedIntRect() {
+  static const mozilla::gfx::IntRect r(0, 0, INT32_MAX, INT32_MAX);
+  return r;
+}
+
+
+bool nsRect::Overflows() const {
+#ifdef NS_COORD_IS_FLOAT
+  return false;
+#else
+  mozilla::CheckedInt<int32_t> xMost = this->x;
+  xMost += this->width;
+  mozilla::CheckedInt<int32_t> yMost = this->y;
+  yMost += this->height;
+  return !xMost.isValid() || !yMost.isValid();
+#endif
+}
+
+#ifdef DEBUG
+// Diagnostics
+
+FILE* operator<<(FILE* out, const nsRect& rect)
+{
+  nsAutoString tmp;
+
+  // Output the coordinates in fractional pixels so they're easier to read
+  tmp.Append('{');
+  tmp.AppendFloat(NSAppUnitsToFloatPixels(rect.x,
+                       nsDeviceContext::AppUnitsPerCSSPixel()));
+  tmp.AppendLiteral(", ");
+  tmp.AppendFloat(NSAppUnitsToFloatPixels(rect.y,
+                       nsDeviceContext::AppUnitsPerCSSPixel()));
+  tmp.AppendLiteral(", ");
+  tmp.AppendFloat(NSAppUnitsToFloatPixels(rect.width,
+                       nsDeviceContext::AppUnitsPerCSSPixel()));
+  tmp.AppendLiteral(", ");
+  tmp.AppendFloat(NSAppUnitsToFloatPixels(rect.height,
+                       nsDeviceContext::AppUnitsPerCSSPixel()));
+  tmp.Append('}');
+  fputs(NS_LossyConvertUTF16toASCII(tmp).get(), out);
+  return out;
+}
+
+#endif // DEBUG
diff --git a/gfx/src/nsRect.h b/gfx/src/nsRect.h
new file mode 100644
index 000000000..267f5849c
--- /dev/null
+++ b/gfx/src/nsRect.h
@@ -0,0 +1,324 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+
+#ifndef NSRECT_H
+#define NSRECT_H
+
+#include <stdio.h>                      // for FILE
+#include <stdint.h>                     // for int32_t, int64_t
+#include <algorithm>                    // for min/max
+#include "mozilla/Likely.h"             // for MOZ_UNLIKELY
+#include "mozilla/gfx/Rect.h"
+#include "nsCoord.h"                    // for nscoord, etc
+#include "nsISupportsImpl.h"            // for MOZ_COUNT_CTOR, etc
+#include "nsPoint.h"                    // for nsIntPoint, nsPoint
+#include "nsMargin.h"                   // for nsIntMargin, nsMargin
+#include "nsSize.h"                     // for IntSize, nsSize
+#include "nscore.h"                     // for NS_BUILD_REFCNT_LOGGING
+
+typedef mozilla::gfx::IntRect nsIntRect;
+
+struct nsRect :
+  public mozilla::gfx::BaseRect<nscoord, nsRect, nsPoint, nsSize, nsMargin> {
+  typedef mozilla::gfx::BaseRect<nscoord, nsRect, nsPoint, nsSize, nsMargin> Super;
+
+  static void VERIFY_COORD(nscoord aValue) { ::VERIFY_COORD(aValue); }
+
+  // Constructors
+  nsRect() : Super()
+  {
+    MOZ_COUNT_CTOR(nsRect);
+  }
+  nsRect(const nsRect& aRect) : Super(aRect)
+  {
+    MOZ_COUNT_CTOR(nsRect);
+  }
+  nsRect(const nsPoint& aOrigin, const nsSize &aSize) : Super(aOrigin, aSize)
+  {
+    MOZ_COUNT_CTOR(nsRect);
+  }
+  nsRect(nscoord aX, nscoord aY, nscoord aWidth, nscoord aHeight) :
+      Super(aX, aY, aWidth, aHeight)
+  {
+    MOZ_COUNT_CTOR(nsRect);
+  }
+
+#ifdef NS_BUILD_REFCNT_LOGGING
+  ~nsRect() {
+    MOZ_COUNT_DTOR(nsRect);
+  }
+#endif
+
+  // We have saturating versions of all the Union methods. These avoid
+  // overflowing nscoord values in the 'width' and 'height' fields by
+  // clamping the width and height values to nscoord_MAX if necessary.
+
+  MOZ_MUST_USE nsRect SaturatingUnion(const nsRect& aRect) const
+  {
+    if (IsEmpty()) {
+      return aRect;
+    } else if (aRect.IsEmpty()) {
+      return *static_cast<const nsRect*>(this);
+    } else {
+      return SaturatingUnionEdges(aRect);
+    }
+  }
+
+  MOZ_MUST_USE nsRect SaturatingUnionEdges(const nsRect& aRect) const
+  {
+#ifdef NS_COORD_IS_FLOAT
+    return UnionEdges(aRect);
+#else
+    nsRect result;
+    result.x = std::min(aRect.x, x);
+    int64_t w = std::max(int64_t(aRect.x) + aRect.width, int64_t(x) + width) - result.x;
+    if (MOZ_UNLIKELY(w > nscoord_MAX)) {
+      // Clamp huge negative x to nscoord_MIN / 2 and try again.
+      result.x = std::max(result.x, nscoord_MIN / 2);
+      w = std::max(int64_t(aRect.x) + aRect.width, int64_t(x) + width) - result.x;
+      if (MOZ_UNLIKELY(w > nscoord_MAX)) {
+        w = nscoord_MAX;
+      }
+    }
+    result.width = nscoord(w);
+
+    result.y = std::min(aRect.y, y);
+    int64_t h = std::max(int64_t(aRect.y) + aRect.height, int64_t(y) + height) - result.y;
+    if (MOZ_UNLIKELY(h > nscoord_MAX)) {
+      // Clamp huge negative y to nscoord_MIN / 2 and try again.
+      result.y = std::max(result.y, nscoord_MIN / 2);
+      h = std::max(int64_t(aRect.y) + aRect.height, int64_t(y) + height) - result.y;
+      if (MOZ_UNLIKELY(h > nscoord_MAX)) {
+        h = nscoord_MAX;
+      }
+    }
+    result.height = nscoord(h);
+    return result;
+#endif
+  }
+
+#ifndef NS_COORD_IS_FLOAT
+  // Make all nsRect Union methods be saturating.
+  MOZ_MUST_USE nsRect UnionEdges(const nsRect& aRect) const
+  {
+    return SaturatingUnionEdges(aRect);
+  }
+  void UnionRectEdges(const nsRect& aRect1, const nsRect& aRect2)
+  {
+    *this = aRect1.UnionEdges(aRect2);
+  }
+  MOZ_MUST_USE nsRect Union(const nsRect& aRect) const
+  {
+    return SaturatingUnion(aRect);
+  }
+  void UnionRect(const nsRect& aRect1, const nsRect& aRect2)
+  {
+    *this = aRect1.Union(aRect2);
+  }
+#endif
+
+  void SaturatingUnionRect(const nsRect& aRect1, const nsRect& aRect2)
+  {
+    *this = aRect1.SaturatingUnion(aRect2);
+  }
+  void SaturatingUnionRectEdges(const nsRect& aRect1, const nsRect& aRect2)
+  {
+    *this = aRect1.SaturatingUnionEdges(aRect2);
+  }
+
+  // Return whether this rect's right or bottom edge overflow int32.
+  bool Overflows() const;
+
+  /**
+   * Return this rect scaled to a different appunits per pixel (APP) ratio.
+   * In the RoundOut version we make the rect the smallest rect containing the
+   * unrounded result. In the RoundIn version we make the rect the largest rect
+   * contained in the unrounded result.
+   * @param aFromAPP the APP to scale from
+   * @param aToAPP the APP to scale to
+   * @note this can turn an empty rectangle into a non-empty rectangle
+   */
+  MOZ_MUST_USE inline nsRect
+    ScaleToOtherAppUnitsRoundOut(int32_t aFromAPP, int32_t aToAPP) const;
+  MOZ_MUST_USE inline nsRect
+    ScaleToOtherAppUnitsRoundIn(int32_t aFromAPP, int32_t aToAPP) const;
+
+  MOZ_MUST_USE inline mozilla::gfx::IntRect
+  ScaleToNearestPixels(float aXScale, float aYScale,
+                       nscoord aAppUnitsPerPixel) const;
+
+  MOZ_MUST_USE inline mozilla::gfx::IntRect
+  ToNearestPixels(nscoord aAppUnitsPerPixel) const;
+
+  // Note: this can turn an empty rectangle into a non-empty rectangle
+  MOZ_MUST_USE inline mozilla::gfx::IntRect
+  ScaleToOutsidePixels(float aXScale, float aYScale,
+                       nscoord aAppUnitsPerPixel) const;
+
+  // Note: this can turn an empty rectangle into a non-empty rectangle
+  MOZ_MUST_USE inline mozilla::gfx::IntRect
+  ToOutsidePixels(nscoord aAppUnitsPerPixel) const;
+
+  MOZ_MUST_USE inline mozilla::gfx::IntRect
+  ScaleToInsidePixels(float aXScale, float aYScale,
+                      nscoord aAppUnitsPerPixel) const;
+
+  MOZ_MUST_USE inline mozilla::gfx::IntRect
+  ToInsidePixels(nscoord aAppUnitsPerPixel) const;
+
+  // This is here only to keep IPDL-generated code happy. DO NOT USE.
+  bool operator==(const nsRect& aRect) const
+  {
+    return IsEqualEdges(aRect);
+  }
+
+  MOZ_MUST_USE inline nsRect RemoveResolution(const float aResolution) const;
+};
+
+/*
+ * App Unit/Pixel conversions
+ */
+
+inline nsRect
+nsRect::ScaleToOtherAppUnitsRoundOut(int32_t aFromAPP, int32_t aToAPP) const
+{
+  if (aFromAPP == aToAPP) {
+    return *this;
+  }
+
+  nsRect rect;
+  nscoord right = NSToCoordCeil(NSCoordScale(XMost(), aFromAPP, aToAPP));
+  nscoord bottom = NSToCoordCeil(NSCoordScale(YMost(), aFromAPP, aToAPP));
+  rect.x = NSToCoordFloor(NSCoordScale(x, aFromAPP, aToAPP));
+  rect.y = NSToCoordFloor(NSCoordScale(y, aFromAPP, aToAPP));
+  rect.width = (right - rect.x);
+  rect.height = (bottom - rect.y);
+
+  return rect;
+}
+
+inline nsRect
+nsRect::ScaleToOtherAppUnitsRoundIn(int32_t aFromAPP, int32_t aToAPP) const
+{
+  if (aFromAPP == aToAPP) {
+    return *this;
+  }
+
+  nsRect rect;
+  nscoord right = NSToCoordFloor(NSCoordScale(XMost(), aFromAPP, aToAPP));
+  nscoord bottom = NSToCoordFloor(NSCoordScale(YMost(), aFromAPP, aToAPP));
+  rect.x = NSToCoordCeil(NSCoordScale(x, aFromAPP, aToAPP));
+  rect.y = NSToCoordCeil(NSCoordScale(y, aFromAPP, aToAPP));
+  rect.width = (right - rect.x);
+  rect.height = (bottom - rect.y);
+
+  return rect;
+}
+
+// scale the rect but round to preserve centers
+inline mozilla::gfx::IntRect
+nsRect::ScaleToNearestPixels(float aXScale, float aYScale,
+                             nscoord aAppUnitsPerPixel) const
+{
+  mozilla::gfx::IntRect rect;
+  rect.x = NSToIntRoundUp(NSAppUnitsToDoublePixels(x, aAppUnitsPerPixel) * aXScale);
+  rect.y = NSToIntRoundUp(NSAppUnitsToDoublePixels(y, aAppUnitsPerPixel) * aYScale);
+  // Avoid negative widths and heights due to overflow
+  rect.width  = std::max(0, NSToIntRoundUp(NSAppUnitsToDoublePixels(XMost(),
+                               aAppUnitsPerPixel) * aXScale) - rect.x);
+  rect.height = std::max(0, NSToIntRoundUp(NSAppUnitsToDoublePixels(YMost(),
+                               aAppUnitsPerPixel) * aYScale) - rect.y);
+  return rect;
+}
+
+// scale the rect but round to smallest containing rect
+inline mozilla::gfx::IntRect
+nsRect::ScaleToOutsidePixels(float aXScale, float aYScale,
+                             nscoord aAppUnitsPerPixel) const
+{
+  mozilla::gfx::IntRect rect;
+  rect.x = NSToIntFloor(NSAppUnitsToFloatPixels(x, float(aAppUnitsPerPixel)) * aXScale);
+  rect.y = NSToIntFloor(NSAppUnitsToFloatPixels(y, float(aAppUnitsPerPixel)) * aYScale);
+  // Avoid negative widths and heights due to overflow
+  rect.width  = std::max(0, NSToIntCeil(NSAppUnitsToFloatPixels(XMost(),
+                            float(aAppUnitsPerPixel)) * aXScale) - rect.x);
+  rect.height = std::max(0, NSToIntCeil(NSAppUnitsToFloatPixels(YMost(),
+                            float(aAppUnitsPerPixel)) * aYScale) - rect.y);
+  return rect;
+}
+
+// scale the rect but round to largest contained rect
+inline mozilla::gfx::IntRect
+nsRect::ScaleToInsidePixels(float aXScale, float aYScale,
+                            nscoord aAppUnitsPerPixel) const
+{
+  mozilla::gfx::IntRect rect;
+  rect.x = NSToIntCeil(NSAppUnitsToFloatPixels(x, float(aAppUnitsPerPixel)) * aXScale);
+  rect.y = NSToIntCeil(NSAppUnitsToFloatPixels(y, float(aAppUnitsPerPixel)) * aYScale);
+  // Avoid negative widths and heights due to overflow
+  rect.width  = std::max(0, NSToIntFloor(NSAppUnitsToFloatPixels(XMost(),
+                             float(aAppUnitsPerPixel)) * aXScale) - rect.x);
+  rect.height = std::max(0, NSToIntFloor(NSAppUnitsToFloatPixels(YMost(),
+                             float(aAppUnitsPerPixel)) * aYScale) - rect.y);
+  return rect;
+}
+
+inline mozilla::gfx::IntRect
+nsRect::ToNearestPixels(nscoord aAppUnitsPerPixel) const
+{
+  return ScaleToNearestPixels(1.0f, 1.0f, aAppUnitsPerPixel);
+}
+
+inline mozilla::gfx::IntRect
+nsRect::ToOutsidePixels(nscoord aAppUnitsPerPixel) const
+{
+  return ScaleToOutsidePixels(1.0f, 1.0f, aAppUnitsPerPixel);
+}
+
+inline mozilla::gfx::IntRect
+nsRect::ToInsidePixels(nscoord aAppUnitsPerPixel) const
+{
+  return ScaleToInsidePixels(1.0f, 1.0f, aAppUnitsPerPixel);
+}
+
+inline nsRect
+nsRect::RemoveResolution(const float aResolution) const
+{
+  MOZ_ASSERT(aResolution > 0.0f);
+  nsRect rect;
+  rect.x = NSToCoordRound(NSCoordToFloat(x) / aResolution);
+  rect.y = NSToCoordRound(NSCoordToFloat(y) / aResolution);
+  // A 1x1 rect indicates we are just hit testing a point, so pass down a 1x1
+  // rect as well instead of possibly rounding the width or height to zero.
+  if (width == 1 && height == 1) {
+    rect.width = rect.height = 1;
+  } else {
+    rect.width = NSToCoordCeil(NSCoordToFloat(width) / aResolution);
+    rect.height = NSToCoordCeil(NSCoordToFloat(height) / aResolution);
+  }
+
+  return rect;
+}
+
+const mozilla::gfx::IntRect& GetMaxSizedIntRect();
+
+// app units are integer multiples of pixels, so no rounding needed
+template<class units>
+nsRect
+ToAppUnits(const mozilla::gfx::IntRectTyped<units>& aRect, nscoord aAppUnitsPerPixel)
+{
+  return nsRect(NSIntPixelsToAppUnits(aRect.x, aAppUnitsPerPixel),
+                NSIntPixelsToAppUnits(aRect.y, aAppUnitsPerPixel),
+                NSIntPixelsToAppUnits(aRect.width, aAppUnitsPerPixel),
+                NSIntPixelsToAppUnits(aRect.height, aAppUnitsPerPixel));
+}
+
+#ifdef DEBUG
+// Diagnostics
+extern FILE* operator<<(FILE* out, const nsRect& rect);
+#endif // DEBUG
+
+#endif /* NSRECT_H */
diff --git a/gfx/src/nsRegion.cpp b/gfx/src/nsRegion.cpp
new file mode 100644
index 000000000..3b0bec1e3
--- /dev/null
+++ b/gfx/src/nsRegion.cpp
@@ -0,0 +1,1146 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+
+#include "nsRegion.h"
+#include "nsTArray.h"
+#include "gfxUtils.h"
+#include "mozilla/ToString.h"
+
+bool nsRegion::Contains(const nsRegion& aRgn) const
+{
+  // XXX this could be made faster by iterating over
+  // both regions at the same time some how
+  for (auto iter = aRgn.RectIter(); !iter.Done(); iter.Next()) {
+    if (!Contains(iter.Get())) {
+      return false;
+    }
+  }
+  return true;
+}
+
+bool nsRegion::Intersects(const nsRect& aRect) const
+{
+  // XXX this could be made faster by using pixman_region32_contains_rect
+  for (auto iter = RectIter(); !iter.Done(); iter.Next()) {
+    if (iter.Get().Intersects(aRect)) {
+      return true;
+    }
+  }
+  return false;
+}
+
+void nsRegion::Inflate(const nsMargin& aMargin)
+{
+  int n;
+  pixman_box32_t *boxes = pixman_region32_rectangles(&mImpl, &n);
+  for (int i=0; i<n; i++) {
+    nsRect rect = BoxToRect(boxes[i]);
+    rect.Inflate(aMargin);
+    boxes[i] = RectToBox(rect);
+  }
+
+  pixman_region32_t region;
+  // This will union all of the rectangles and runs in about O(n lg(n))
+  pixman_region32_init_rects(&region, boxes, n);
+
+  pixman_region32_fini(&mImpl);
+  mImpl = region;
+}
+
+void nsRegion::SimplifyOutward (uint32_t aMaxRects)
+{
+  MOZ_ASSERT(aMaxRects >= 1, "Invalid max rect count");
+
+  if (GetNumRects() <= aMaxRects)
+    return;
+
+  pixman_box32_t *boxes;
+  int n;
+  boxes = pixman_region32_rectangles(&mImpl, &n);
+
+  // Try combining rects in horizontal bands into a single rect
+  int dest = 0;
+  for (int src = 1; src < n; src++)
+  {
+    // The goal here is to try to keep groups of rectangles that are vertically
+    // discontiguous as separate rectangles in the final region. This is
+    // simple and fast to implement and page contents tend to vary more
+    // vertically than horizontally (which is why our rectangles are stored
+    // sorted by y-coordinate, too).
+    //
+    // Note: if boxes share y1 because of the canonical representation they
+    // will share y2
+    while ((src < (n)) && boxes[dest].y1 == boxes[src].y1) {
+      // merge box[i] and box[i+1]
+      boxes[dest].x2 = boxes[src].x2;
+      src++;
+    }
+    if (src < n) {
+      dest++;
+      boxes[dest] = boxes[src];
+    }
+  }
+
+  uint32_t reducedCount = dest+1;
+  // pixman has a special representation for
+  // regions of 1 rectangle. So just use the
+  // bounds in that case
+  if (reducedCount > 1 && reducedCount <= aMaxRects) {
+    // reach into pixman and lower the number
+    // of rects stored in data.
+    mImpl.data->numRects = reducedCount;
+  } else {
+    *this = GetBounds();
+  }
+}
+
+// compute the covered area difference between two rows.
+// by iterating over both rows simultaneously and adding up
+// the additional increase in area caused by extending each
+// of the rectangles to the combined height of both rows
+static uint32_t ComputeMergedAreaIncrease(pixman_box32_t *topRects,
+		                     pixman_box32_t *topRectsEnd,
+		                     pixman_box32_t *bottomRects,
+		                     pixman_box32_t *bottomRectsEnd)
+{
+  uint32_t totalArea = 0;
+  struct pt {
+    int32_t x, y;
+  };
+
+
+  pt *i = (pt*)topRects;
+  pt *end_i = (pt*)topRectsEnd;
+  pt *j = (pt*)bottomRects;
+  pt *end_j = (pt*)bottomRectsEnd;
+  bool top = false;
+  bool bottom = false;
+
+  int cur_x = i->x;
+  bool top_next = top;
+  bool bottom_next = bottom;
+  //XXX: we could probably simplify this condition and perhaps move it into the loop below
+  if (j->x < cur_x) {
+    cur_x = j->x;
+    j++;
+    bottom_next = !bottom;
+  } else if (j->x == cur_x) {
+    i++;
+    top_next = !top;
+    bottom_next = !bottom;
+    j++;
+  } else {
+    top_next = !top;
+    i++;
+  }
+
+  int topRectsHeight = topRects->y2 - topRects->y1;
+  int bottomRectsHeight = bottomRects->y2 - bottomRects->y1;
+  int inbetweenHeight = bottomRects->y1 - topRects->y2;
+  int width = cur_x;
+  // top and bottom are the in-status to the left of cur_x
+  do {
+    if (top && !bottom) {
+      totalArea += (inbetweenHeight+bottomRectsHeight)*width;
+    } else if (bottom && !top) {
+      totalArea += (inbetweenHeight+topRectsHeight)*width;
+    } else if (bottom && top) {
+      totalArea += (inbetweenHeight)*width;
+    }
+    top = top_next;
+    bottom = bottom_next;
+    // find the next edge
+    if (i->x < j->x) {
+      top_next = !top;
+      width = i->x - cur_x;
+      cur_x = i->x;
+      i++;
+    } else if (j->x < i->x) {
+      bottom_next = !bottom;
+      width = j->x - cur_x;
+      cur_x = j->x;
+      j++;
+    } else { // i->x == j->x
+      top_next = !top;
+      bottom_next = !bottom;
+      width = i->x - cur_x;
+      cur_x = i->x;
+      i++;
+      j++;
+    }
+  } while (i < end_i && j < end_j);
+
+  // handle any remaining rects
+  while (i < end_i) {
+    width = i->x - cur_x;
+    cur_x = i->x;
+    i++;
+    if (top)
+      totalArea += (inbetweenHeight+bottomRectsHeight)*width;
+    top = !top;
+  }
+
+  while (j < end_j) {
+    width = j->x - cur_x;
+    cur_x = j->x;
+    j++;
+    if (bottom)
+      totalArea += (inbetweenHeight+topRectsHeight)*width;
+    bottom = !bottom;
+  }
+  return totalArea;
+}
+
+static pixman_box32_t *
+CopyRow(pixman_box32_t *dest_it, pixman_box32_t *src_start, pixman_box32_t *src_end)
+{
+    // XXX: std::copy
+    pixman_box32_t *src_it = src_start;
+    while (src_it < src_end) {
+        *dest_it++ = *src_it++;
+    }
+    return dest_it;
+}
+
+
+#define WRITE_RECT(x1, x2, y1, y2) \
+    do {                    \
+         tmpRect->x1 = x1;  \
+         tmpRect->x2 = x2;  \
+         tmpRect->y1 = y1;  \
+         tmpRect->y2 = y2;  \
+         tmpRect++;         \
+    } while (0)
+
+/* If 'r' overlaps the current rect, then expand the current rect to include
+ * it. Otherwise write the current rect out to tmpRect, and set r as the
+ * updated current rect. */
+#define MERGE_RECT(r)                 \
+    do {                              \
+      if (r->x1 <= x2) {              \
+          if (x2 < r->x2)             \
+              x2 = r->x2;             \
+      } else {                        \
+          WRITE_RECT(x1, x2, y1, y2); \
+          x1 = r->x1;                 \
+          x2 = r->x2;                 \
+      }                               \
+      r++;                            \
+    } while (0)
+
+
+/* Can we merge two sets of rects without extra space?
+ * Yes, but not easily. We can even do it stably
+ * but we don't need that property.
+ *
+ * This is written in the style of pixman_region_union_o */
+static pixman_box32_t *
+MergeRects(pixman_box32_t *r1,
+           pixman_box32_t *r1_end,
+           pixman_box32_t *r2,
+           pixman_box32_t *r2_end,
+           pixman_box32_t *tmpRect)
+{
+    /* This routine works by maintaining the current
+     * rectangle in x1,x2,y1,y2 and either merging
+     * in the left most rectangle if it overlaps or
+     * outputing the current rectangle and setting
+     * it to the the left most one */
+    const int y1 = r1->y1;
+    const int y2 = r2->y2;
+    int x1;
+    int x2;
+
+    /* Find the left-most edge */
+    if (r1->x1 < r2->x1) {
+        x1 = r1->x1;
+        x2 = r1->x2;
+        r1++;
+    } else {
+        x1 = r2->x1;
+        x2 = r2->x2;
+        r2++;
+    }
+
+    while (r1 != r1_end && r2 != r2_end) {
+        /* Find and merge the left-most rectangle */
+        if (r1->x1 < r2->x1)
+            MERGE_RECT (r1);
+        else
+            MERGE_RECT (r2);
+    }
+
+    /* Finish up any left overs */
+    if (r1 != r1_end) {
+        do {
+            MERGE_RECT (r1);
+        } while (r1 != r1_end);
+    } else if (r2 != r2_end) {
+        do {
+            MERGE_RECT(r2);
+        } while (r2 != r2_end);
+    }
+
+    /* Finish up the last rectangle */
+    WRITE_RECT(x1, x2, y1, y2);
+
+    return tmpRect;
+}
+
+void nsRegion::SimplifyOutwardByArea(uint32_t aThreshold)
+{
+
+  pixman_box32_t *boxes;
+  int n;
+  boxes = pixman_region32_rectangles(&mImpl, &n);
+
+  // if we have no rectangles then we're done
+  if (!n)
+    return;
+
+  pixman_box32_t *end = boxes + n;
+  pixman_box32_t *topRectsEnd = boxes+1;
+  pixman_box32_t *topRects = boxes;
+
+  // we need some temporary storage for merging both rows of rectangles
+  AutoTArray<pixman_box32_t, 10> tmpStorage;
+  tmpStorage.SetCapacity(n);
+  pixman_box32_t *tmpRect = tmpStorage.Elements();
+
+  pixman_box32_t *destRect = boxes;
+  pixman_box32_t *rect = tmpRect;
+  // find the end of the first span of rectangles
+  while (topRectsEnd < end && topRectsEnd->y1 == topRects->y1) {
+    topRectsEnd++;
+  }
+
+  // if we only have one row we are done
+  if (topRectsEnd == end)
+    return;
+
+  pixman_box32_t *bottomRects = topRectsEnd;
+  pixman_box32_t *bottomRectsEnd = bottomRects+1;
+  do {
+    // find the end of the bottom span of rectangles
+    while (bottomRectsEnd < end && bottomRectsEnd->y1 == bottomRects->y1) {
+      bottomRectsEnd++;
+    }
+    uint32_t totalArea = ComputeMergedAreaIncrease(topRects, topRectsEnd,
+                                                   bottomRects, bottomRectsEnd);
+
+    if (totalArea <= aThreshold) {
+      // merge the rects into tmpRect
+      rect = MergeRects(topRects, topRectsEnd, bottomRects, bottomRectsEnd, tmpRect);
+
+      // set topRects to where the newly merged rects will be so that we use them
+      // as our next set of topRects
+      topRects = destRect;
+      // copy the merged rects back into the destination
+      topRectsEnd = CopyRow(destRect, tmpRect, rect);
+    } else {
+      // copy the unmerged rects
+      destRect = CopyRow(destRect, topRects, topRectsEnd);
+
+      topRects = bottomRects;
+      topRectsEnd = bottomRectsEnd;
+      if (bottomRectsEnd == end) {
+        // copy the last row when we are done
+        topRectsEnd = CopyRow(destRect, topRects, topRectsEnd);
+      }
+    }
+    bottomRects = bottomRectsEnd;
+  } while (bottomRectsEnd != end);
+
+
+  uint32_t reducedCount = topRectsEnd - pixman_region32_rectangles(&this->mImpl, &n);
+  // pixman has a special representation for
+  // regions of 1 rectangle. So just use the
+  // bounds in that case
+  if (reducedCount > 1) {
+    // reach into pixman and lower the number
+    // of rects stored in data.
+    this->mImpl.data->numRects = reducedCount;
+  } else {
+    *this = GetBounds();
+  }
+}
+
+
+typedef void (*visit_fn)(void *closure, VisitSide side, int x1, int y1, int x2, int y2);
+
+static bool VisitNextEdgeBetweenRect(visit_fn visit, void *closure, VisitSide side,
+				     pixman_box32_t *&r1, pixman_box32_t *&r2, const int y, int &x1)
+{
+  // check for overlap
+  if (r1->x2 >= r2->x1) {
+    MOZ_ASSERT(r2->x1 >= x1);
+    visit(closure, side, x1, y, r2->x1, y);
+
+    // find the rect that ends first or always drop the one that comes first?
+    if (r1->x2 < r2->x2) {
+      x1 = r1->x2;
+      r1++;
+    } else {
+      x1 = r2->x2;
+      r2++;
+    }
+    return true;
+  } else {
+    MOZ_ASSERT(r1->x2 < r2->x2);
+    // we handle the corners by just extending the top and bottom edges
+    visit(closure, side, x1, y, r1->x2+1, y);
+    r1++;
+    // we assign x1 because we can assume that x1 <= r2->x1 - 1
+    // However the caller may know better and if so, may update
+    // x1 to r1->x1
+    x1 = r2->x1 - 1;
+    return false;
+  }
+}
+
+//XXX: if we need to this can compute the end of the row
+static void
+VisitSides(visit_fn visit, void *closure, pixman_box32_t *r, pixman_box32_t *r_end)
+{
+  // XXX: we can drop LEFT/RIGHT and just use the orientation
+  // of the line if it makes sense
+  while (r != r_end) {
+    visit(closure, VisitSide::LEFT, r->x1, r->y1, r->x1, r->y2);
+    visit(closure, VisitSide::RIGHT, r->x2, r->y1, r->x2, r->y2);
+    r++;
+  }
+}
+
+static void
+VisitAbove(visit_fn visit, void *closure, pixman_box32_t *r, pixman_box32_t *r_end)
+{
+  while (r != r_end) {
+    visit(closure, VisitSide::TOP, r->x1-1, r->y1, r->x2+1, r->y1);
+    r++;
+  }
+}
+
+static void
+VisitBelow(visit_fn visit, void *closure, pixman_box32_t *r, pixman_box32_t *r_end)
+{
+  while (r != r_end) {
+    visit(closure, VisitSide::BOTTOM, r->x1-1, r->y2, r->x2+1, r->y2);
+    r++;
+  }
+}
+
+static pixman_box32_t *
+VisitInbetween(visit_fn visit, void *closure, pixman_box32_t *r1,
+               pixman_box32_t *r1_end,
+               pixman_box32_t *r2,
+               pixman_box32_t *r2_end)
+{
+  const int y = r1->y2;
+  int x1;
+
+  bool overlap = false;
+  while (r1 != r1_end && r2 != r2_end) {
+    if (!overlap) {
+      /* Find the left-most edge */
+      if (r1->x1 < r2->x1) {
+	x1 = r1->x1 - 1;
+      } else {
+	x1 = r2->x1 - 1;
+      }
+    }
+
+    MOZ_ASSERT((x1 >= (r1->x1 - 1)) || (x1 >= (r2->x1 - 1)));
+    if (r1->x1 < r2->x1) {
+      overlap = VisitNextEdgeBetweenRect(visit, closure, VisitSide::BOTTOM, r1, r2, y, x1);
+    } else {
+      overlap = VisitNextEdgeBetweenRect(visit, closure, VisitSide::TOP, r2, r1, y, x1);
+    }
+  }
+
+  /* Finish up which ever row has remaining rects*/
+  if (r1 != r1_end) {
+    // top row
+    do {
+      visit(closure, VisitSide::BOTTOM, x1, y, r1->x2 + 1, y);
+      r1++;
+      if (r1 == r1_end)
+	break;
+      x1 = r1->x1 - 1;
+    } while (true);
+  } else if (r2 != r2_end) {
+    // bottom row
+    do {
+      visit(closure, VisitSide::TOP, x1, y, r2->x2 + 1, y);
+      r2++;
+      if (r2 == r2_end)
+	break;
+      x1 = r2->x1 - 1;
+    } while (true);
+  }
+
+  return 0;
+}
+
+void nsRegion::VisitEdges (visit_fn visit, void *closure)
+{
+  pixman_box32_t *boxes;
+  int n;
+  boxes = pixman_region32_rectangles(&mImpl, &n);
+
+  // if we have no rectangles then we're done
+  if (!n)
+    return;
+
+  pixman_box32_t *end = boxes + n;
+  pixman_box32_t *topRectsEnd = boxes + 1;
+  pixman_box32_t *topRects = boxes;
+
+  // find the end of the first span of rectangles
+  while (topRectsEnd < end && topRectsEnd->y1 == topRects->y1) {
+    topRectsEnd++;
+  }
+
+  // In order to properly handle convex corners we always visit the sides first
+  // that way when we visit the corners we can pad using the value from the sides
+  VisitSides(visit, closure, topRects, topRectsEnd);
+
+  VisitAbove(visit, closure, topRects, topRectsEnd);
+
+  pixman_box32_t *bottomRects = topRects;
+  pixman_box32_t *bottomRectsEnd = topRectsEnd;
+  if (topRectsEnd != end) {
+    do {
+      // find the next row of rects
+      bottomRects = topRectsEnd;
+      bottomRectsEnd = topRectsEnd + 1;
+      while (bottomRectsEnd < end && bottomRectsEnd->y1 == bottomRects->y1) {
+        bottomRectsEnd++;
+      }
+
+      VisitSides(visit, closure, bottomRects, bottomRectsEnd);
+
+      if (topRects->y2 == bottomRects->y1) {
+        VisitInbetween(visit, closure, topRects, topRectsEnd,
+                                       bottomRects, bottomRectsEnd);
+      } else {
+        VisitBelow(visit, closure, topRects, topRectsEnd);
+        VisitAbove(visit, closure, bottomRects, bottomRectsEnd);
+      }
+
+      topRects = bottomRects;
+      topRectsEnd = bottomRectsEnd;
+    } while (bottomRectsEnd != end);
+  }
+
+  // the bottom of the region doesn't touch anything else so we
+  // can always visit it at the end
+  VisitBelow(visit, closure, bottomRects, bottomRectsEnd);
+}
+
+
+void nsRegion::SimplifyInward (uint32_t aMaxRects)
+{
+  NS_ASSERTION(aMaxRects >= 1, "Invalid max rect count");
+
+  if (GetNumRects() <= aMaxRects)
+    return;
+
+  SetEmpty();
+}
+
+uint64_t nsRegion::Area () const
+{
+  uint64_t area = 0;
+  for (auto iter = RectIter(); !iter.Done(); iter.Next()) {
+    const nsRect& rect = iter.Get();
+    area += uint64_t(rect.width) * rect.height;
+  }
+  return area;
+}
+
+nsRegion& nsRegion::ScaleRoundOut (float aXScale, float aYScale)
+{
+  if (mozilla::gfx::FuzzyEqual(aXScale, 1.0f) &&
+      mozilla::gfx::FuzzyEqual(aYScale, 1.0f)) {
+    return *this;
+  }
+
+  int n;
+  pixman_box32_t *boxes = pixman_region32_rectangles(&mImpl, &n);
+  for (int i=0; i<n; i++) {
+    nsRect rect = BoxToRect(boxes[i]);
+    rect.ScaleRoundOut(aXScale, aYScale);
+    boxes[i] = RectToBox(rect);
+  }
+
+  pixman_region32_t region;
+  // This will union all of the rectangles and runs in about O(n lg(n))
+  pixman_region32_init_rects(&region, boxes, n);
+
+  pixman_region32_fini(&mImpl);
+  mImpl = region;
+  return *this;
+}
+
+nsRegion& nsRegion::ScaleInverseRoundOut (float aXScale, float aYScale)
+{
+  int n;
+  pixman_box32_t *boxes = pixman_region32_rectangles(&mImpl, &n);
+  for (int i=0; i<n; i++) {
+    nsRect rect = BoxToRect(boxes[i]);
+    rect.ScaleInverseRoundOut(aXScale, aYScale);
+    boxes[i] = RectToBox(rect);
+  }
+
+  pixman_region32_t region;
+  // This will union all of the rectangles and runs in about O(n lg(n))
+  pixman_region32_init_rects(&region, boxes, n);
+
+  pixman_region32_fini(&mImpl);
+  mImpl = region;
+  return *this;
+}
+
+static mozilla::gfx::IntRect
+TransformRect(const mozilla::gfx::IntRect& aRect, const mozilla::gfx::Matrix4x4& aTransform)
+{
+    if (aRect.IsEmpty()) {
+        return mozilla::gfx::IntRect();
+    }
+
+    mozilla::gfx::RectDouble rect(aRect.x, aRect.y, aRect.width, aRect.height);
+    rect = aTransform.TransformAndClipBounds(rect, mozilla::gfx::RectDouble::MaxIntRect());
+    rect.RoundOut();
+
+    mozilla::gfx::IntRect intRect;
+    if (!gfxUtils::GfxRectToIntRect(ThebesRect(rect), &intRect)) {
+        return mozilla::gfx::IntRect();
+    }
+
+    return intRect;
+}
+
+nsRegion& nsRegion::Transform (const mozilla::gfx::Matrix4x4 &aTransform)
+{
+  int n;
+  pixman_box32_t *boxes = pixman_region32_rectangles(&mImpl, &n);
+  for (int i=0; i<n; i++) {
+    nsRect rect = BoxToRect(boxes[i]);
+    boxes[i] = RectToBox(nsIntRegion::ToRect(TransformRect(nsIntRegion::FromRect(rect), aTransform)));
+  }
+
+  pixman_region32_t region;
+  // This will union all of the rectangles and runs in about O(n lg(n))
+  pixman_region32_init_rects(&region, boxes, n);
+
+  pixman_region32_fini(&mImpl);
+  mImpl = region;
+  return *this;
+}
+
+
+nsRegion nsRegion::ScaleToOtherAppUnitsRoundOut (int32_t aFromAPP, int32_t aToAPP) const
+{
+  if (aFromAPP == aToAPP) {
+    return *this;
+  }
+
+  nsRegion region = *this;
+  int n;
+  pixman_box32_t *boxes = pixman_region32_rectangles(&region.mImpl, &n);
+  for (int i=0; i<n; i++) {
+    nsRect rect = BoxToRect(boxes[i]);
+    rect = rect.ScaleToOtherAppUnitsRoundOut(aFromAPP, aToAPP);
+    boxes[i] = RectToBox(rect);
+  }
+
+  pixman_region32_t pixmanRegion;
+  // This will union all of the rectangles and runs in about O(n lg(n))
+  pixman_region32_init_rects(&pixmanRegion, boxes, n);
+
+  pixman_region32_fini(&region.mImpl);
+  region.mImpl = pixmanRegion;
+  return region;
+}
+
+nsRegion nsRegion::ScaleToOtherAppUnitsRoundIn (int32_t aFromAPP, int32_t aToAPP) const
+{
+  if (aFromAPP == aToAPP) {
+    return *this;
+  }
+
+  nsRegion region = *this;
+  int n;
+  pixman_box32_t *boxes = pixman_region32_rectangles(&region.mImpl, &n);
+  for (int i=0; i<n; i++) {
+    nsRect rect = BoxToRect(boxes[i]);
+    rect = rect.ScaleToOtherAppUnitsRoundIn(aFromAPP, aToAPP);
+    boxes[i] = RectToBox(rect);
+  }
+
+  pixman_region32_t pixmanRegion;
+  // This will union all of the rectangles and runs in about O(n lg(n))
+  pixman_region32_init_rects(&pixmanRegion, boxes, n);
+
+  pixman_region32_fini(&region.mImpl);
+  region.mImpl = pixmanRegion;
+  return region;
+}
+
+nsIntRegion nsRegion::ToPixels (nscoord aAppUnitsPerPixel, bool aOutsidePixels) const
+{
+  nsRegion region = *this;
+  int n;
+  pixman_box32_t *boxes = pixman_region32_rectangles(&region.mImpl, &n);
+  for (int i=0; i<n; i++) {
+    nsRect rect = BoxToRect(boxes[i]);
+    mozilla::gfx::IntRect deviceRect;
+    if (aOutsidePixels)
+      deviceRect = rect.ToOutsidePixels(aAppUnitsPerPixel);
+    else
+      deviceRect = rect.ToNearestPixels(aAppUnitsPerPixel);
+
+    boxes[i] = RectToBox(deviceRect);
+  }
+
+  nsIntRegion intRegion;
+  pixman_region32_fini(&intRegion.mImpl.mImpl);
+  // This will union all of the rectangles and runs in about O(n lg(n))
+  pixman_region32_init_rects(&intRegion.mImpl.mImpl, boxes, n);
+
+  return intRegion;
+}
+
+nsIntRegion nsRegion::ToOutsidePixels (nscoord aAppUnitsPerPixel) const
+{
+  return ToPixels(aAppUnitsPerPixel, true);
+}
+
+nsIntRegion nsRegion::ToNearestPixels (nscoord aAppUnitsPerPixel) const
+{
+  return ToPixels(aAppUnitsPerPixel, false);
+}
+
+nsIntRegion nsRegion::ScaleToNearestPixels (float aScaleX, float aScaleY,
+                                            nscoord aAppUnitsPerPixel) const
+{
+  nsIntRegion result;
+  for (auto iter = RectIter(); !iter.Done(); iter.Next()) {
+    mozilla::gfx::IntRect deviceRect =
+      iter.Get().ScaleToNearestPixels(aScaleX, aScaleY, aAppUnitsPerPixel);
+    result.Or(result, deviceRect);
+  }
+  return result;
+}
+
+nsIntRegion nsRegion::ScaleToOutsidePixels (float aScaleX, float aScaleY,
+                                            nscoord aAppUnitsPerPixel) const
+{
+  // make a copy of the region so that we can mutate it inplace
+  nsRegion region = *this;
+  int n;
+  pixman_box32_t *boxes = pixman_region32_rectangles(&region.mImpl, &n);
+  boxes = pixman_region32_rectangles(&region.mImpl, &n);
+  for (int i=0; i<n; i++) {
+    nsRect rect = BoxToRect(boxes[i]);
+    mozilla::gfx::IntRect irect = rect.ScaleToOutsidePixels(aScaleX, aScaleY, aAppUnitsPerPixel);
+    boxes[i] = RectToBox(irect);
+  }
+
+  nsIntRegion iRegion;
+  // clear out the initial pixman_region so that we can replace it below
+  pixman_region32_fini(&iRegion.mImpl.mImpl);
+  // This will union all of the rectangles and runs in about O(n lg(n))
+  pixman_region32_init_rects(&iRegion.mImpl.mImpl, boxes, n);
+
+  return iRegion;
+}
+
+nsIntRegion nsRegion::ScaleToInsidePixels (float aScaleX, float aScaleY,
+                                           nscoord aAppUnitsPerPixel) const
+{
+  /* When scaling a rect, walk forward through the rect list up until the y value is greater
+   * than the current rect's YMost() value.
+   *
+   * For each rect found, check if the rects have a touching edge (in unscaled coordinates),
+   * and if one edge is entirely contained within the other.
+   *
+   * If it is, then the contained edge can be moved (in scaled pixels) to ensure that no
+   * gap exists.
+   *
+   * Since this could be potentially expensive - O(n^2), we only attempt this algorithm
+   * for the first rect.
+   */
+
+  // make a copy of this region so that we can mutate it in place
+  nsRegion region = *this;
+  int n;
+  pixman_box32_t *boxes = pixman_region32_rectangles(&region.mImpl, &n);
+
+  nsIntRegion intRegion;
+  if (n) {
+    nsRect first = BoxToRect(boxes[0]);
+    mozilla::gfx::IntRect firstDeviceRect =
+      first.ScaleToInsidePixels(aScaleX, aScaleY, aAppUnitsPerPixel);
+
+    for (int i=1; i<n; i++) {
+      nsRect rect = nsRect(boxes[i].x1, boxes[i].y1,
+	  boxes[i].x2 - boxes[i].x1,
+	  boxes[i].y2 - boxes[i].y1);
+      mozilla::gfx::IntRect deviceRect =
+	rect.ScaleToInsidePixels(aScaleX, aScaleY, aAppUnitsPerPixel);
+
+      if (rect.y <= first.YMost()) {
+	if (rect.XMost() == first.x && rect.YMost() <= first.YMost()) {
+	  // rect is touching on the left edge of the first rect and contained within
+	  // the length of its left edge
+	  deviceRect.SetRightEdge(firstDeviceRect.x);
+	} else if (rect.x == first.XMost() && rect.YMost() <= first.YMost()) {
+	  // rect is touching on the right edge of the first rect and contained within
+	  // the length of its right edge
+	  deviceRect.SetLeftEdge(firstDeviceRect.XMost());
+	} else if (rect.y == first.YMost()) {
+	  // The bottom of the first rect is on the same line as the top of rect, but
+	  // they aren't necessarily contained.
+	  if (rect.x <= first.x && rect.XMost() >= first.XMost()) {
+	    // The top of rect contains the bottom of the first rect
+	    firstDeviceRect.SetBottomEdge(deviceRect.y);
+	  } else if (rect.x >= first.x && rect.XMost() <= first.XMost()) {
+	    // The bottom of the first contains the top of rect
+	    deviceRect.SetTopEdge(firstDeviceRect.YMost());
+	  }
+	}
+      }
+
+      boxes[i] = RectToBox(deviceRect);
+    }
+
+    boxes[0] = RectToBox(firstDeviceRect);
+
+    pixman_region32_fini(&intRegion.mImpl.mImpl);
+    // This will union all of the rectangles and runs in about O(n lg(n))
+    pixman_region32_init_rects(&intRegion.mImpl.mImpl, boxes, n);
+  }
+  return intRegion;
+
+}
+
+// A cell's "value" is a pair consisting of
+// a) the area of the subrectangle it corresponds to, if it's in
+// aContainingRect and in the region, 0 otherwise
+// b) the area of the subrectangle it corresponds to, if it's in the region,
+// 0 otherwise
+// Addition, subtraction and identity are defined on these values in the
+// obvious way. Partial order is lexicographic.
+// A "large negative value" is defined with large negative numbers for both
+// fields of the pair. This negative value has the property that adding any
+// number of non-negative values to it always results in a negative value.
+//
+// The GetLargestRectangle algorithm works in three phases:
+//  1) Convert the region into a grid by adding vertical/horizontal lines for
+//     each edge of each rectangle in the region.
+//  2) For each rectangle in the region, for each cell it contains, set that
+//     cells's value as described above.
+//  3) Calculate the submatrix with the largest sum such that none of its cells
+//     contain any 0s (empty regions). The rectangle represented by the
+//     submatrix is the largest rectangle in the region.
+//
+// Let k be the number of rectangles in the region.
+// Let m be the height of the grid generated in step 1.
+// Let n be the width of the grid generated in step 1.
+//
+// Step 1 is O(k) in time and O(m+n) in space for the sparse grid.
+// Step 2 is O(mn) in time and O(mn) in additional space for the full grid.
+// Step 3 is O(m^2 n) in time and O(mn) in additional space
+//
+// The implementation of steps 1 and 2 are rather straightforward. However our
+// implementation of step 3 uses dynamic programming to achieve its efficiency.
+//
+// Psuedo code for step 3 is as follows where G is the grid from step 1 and A
+// is the array from step 2:
+// Phase3 = function (G, A, m, n) {
+//   let (t,b,l,r,_) = MaxSum2D(A,m,n)
+//   return rect(G[t],G[l],G[r],G[b]);
+// }
+// MaxSum2D = function (A, m, n) {
+//   S = array(m+1,n+1)
+//   S[0][i] = 0 for i in [0,n]
+//   S[j][0] = 0 for j in [0,m]
+//   S[j][i] = (if A[j-1][i-1] = 0 then some large negative value else A[j-1][i-1])
+//           + S[j-1][n] + S[j][i-1] - S[j-1][i-1]
+//
+//   // top, bottom, left, right, area
+//   var maxRect = (-1, -1, -1, -1, 0);
+//
+//   for all (m',m'') in [0, m]^2 {
+//     let B = { S[m'][i] - S[m''][i] | 0 <= i <= n }
+//     let ((l,r),area) = MaxSum1D(B,n+1)
+//     if (area > maxRect.area) {
+//       maxRect := (m', m'', l, r, area)
+//     }
+//   }
+//
+//   return maxRect;
+// }
+//
+// Originally taken from Improved algorithms for the k-maximum subarray problem
+// for small k - SE Bae, T Takaoka but modified to show the explicit tracking
+// of indices and we already have the prefix sums from our one call site so
+// there's no need to construct them.
+// MaxSum1D = function (A,n) {
+//   var minIdx = 0;
+//   var min = 0;
+//   var maxIndices = (0,0);
+//   var max = 0;
+//   for i in range(n) {
+//     let cand = A[i] - min;
+//     if (cand > max) {
+//       max := cand;
+//       maxIndices := (minIdx, i)
+//     }
+//     if (min > A[i]) {
+//       min := A[i];
+//       minIdx := i;
+//     }
+//   }
+//   return (minIdx, maxIdx, max);
+// }
+
+namespace {
+  // This class represents a partitioning of an axis delineated by coordinates.
+  // It internally maintains a sorted array of coordinates.
+  class AxisPartition {
+  public:
+    // Adds a new partition at the given coordinate to this partitioning. If
+    // the coordinate is already present in the partitioning, this does nothing.
+    void InsertCoord(nscoord c) {
+      uint32_t i = mStops.IndexOfFirstElementGt(c);
+      if (i == 0 || mStops[i-1] != c) {
+        mStops.InsertElementAt(i, c);
+      }
+    }
+
+    // Returns the array index of the given partition point. The partition
+    // point must already be present in the partitioning.
+    int32_t IndexOf(nscoord p) const {
+      return mStops.BinaryIndexOf(p);
+    }
+
+    // Returns the partition at the given index which must be non-zero and
+    // less than the number of partitions in this partitioning.
+    nscoord StopAt(int32_t index) const {
+      return mStops[index];
+    }
+
+    // Returns the size of the gap between the partition at the given index and
+    // the next partition in this partitioning. If the index is the last index
+    // in the partitioning, the result is undefined.
+    nscoord StopSize(int32_t index) const {
+      return mStops[index+1] - mStops[index];
+    }
+
+    // Returns the number of partitions in this partitioning.
+    int32_t GetNumStops() const { return mStops.Length(); }
+
+  private:
+    nsTArray<nscoord> mStops;
+  };
+
+  const int64_t kVeryLargeNegativeNumber = 0xffff000000000000ll;
+
+  struct SizePair {
+    int64_t mSizeContainingRect;
+    int64_t mSize;
+
+    SizePair() : mSizeContainingRect(0), mSize(0) {}
+
+    static SizePair VeryLargeNegative() {
+      SizePair result;
+      result.mSize = result.mSizeContainingRect = kVeryLargeNegativeNumber;
+      return result;
+    }
+    bool operator<(const SizePair& aOther) const {
+      if (mSizeContainingRect < aOther.mSizeContainingRect)
+        return true;
+      if (mSizeContainingRect > aOther.mSizeContainingRect)
+        return false;
+      return mSize < aOther.mSize;
+    }
+    bool operator>(const SizePair& aOther) const {
+      return aOther.operator<(*this);
+    }
+    SizePair operator+(const SizePair& aOther) const {
+      SizePair result = *this;
+      result.mSizeContainingRect += aOther.mSizeContainingRect;
+      result.mSize += aOther.mSize;
+      return result;
+    }
+    SizePair operator-(const SizePair& aOther) const {
+      SizePair result = *this;
+      result.mSizeContainingRect -= aOther.mSizeContainingRect;
+      result.mSize -= aOther.mSize;
+      return result;
+    }
+  };
+
+  // Returns the sum and indices of the subarray with the maximum sum of the
+  // given array (A,n), assuming the array is already in prefix sum form.
+  SizePair MaxSum1D(const nsTArray<SizePair> &A, int32_t n,
+                    int32_t *minIdx, int32_t *maxIdx) {
+    // The min/max indicies of the largest subarray found so far
+    SizePair min, max;
+    int32_t currentMinIdx = 0;
+
+    *minIdx = 0;
+    *maxIdx = 0;
+
+    // Because we're given the array in prefix sum form, we know the first
+    // element is 0
+    for(int32_t i = 1; i < n; i++) {
+      SizePair cand = A[i] - min;
+      if (cand > max) {
+        max = cand;
+        *minIdx = currentMinIdx;
+        *maxIdx = i;
+      }
+      if (min > A[i]) {
+        min = A[i];
+        currentMinIdx = i;
+      }
+    }
+
+    return max;
+  }
+} // namespace
+
+nsRect nsRegion::GetLargestRectangle (const nsRect& aContainingRect) const {
+  nsRect bestRect;
+
+  if (GetNumRects() <= 1) {
+    bestRect = GetBounds();
+    return bestRect;
+  }
+
+  AxisPartition xaxis, yaxis;
+
+  // Step 1: Calculate the grid lines
+  for (auto iter = RectIter(); !iter.Done(); iter.Next()) {
+    const nsRect& rect = iter.Get();
+    xaxis.InsertCoord(rect.x);
+    xaxis.InsertCoord(rect.XMost());
+    yaxis.InsertCoord(rect.y);
+    yaxis.InsertCoord(rect.YMost());
+  }
+  if (!aContainingRect.IsEmpty()) {
+    xaxis.InsertCoord(aContainingRect.x);
+    xaxis.InsertCoord(aContainingRect.XMost());
+    yaxis.InsertCoord(aContainingRect.y);
+    yaxis.InsertCoord(aContainingRect.YMost());
+  }
+
+  // Step 2: Fill out the grid with the areas
+  // Note: due to the ordering of rectangles in the region, it is not always
+  // possible to combine steps 2 and 3 so we don't try to be clever.
+  int32_t matrixHeight = yaxis.GetNumStops() - 1;
+  int32_t matrixWidth = xaxis.GetNumStops() - 1;
+  int32_t matrixSize = matrixHeight * matrixWidth;
+  nsTArray<SizePair> areas(matrixSize);
+  areas.SetLength(matrixSize);
+
+  for (auto iter = RectIter(); !iter.Done(); iter.Next()) {
+    const nsRect& rect = iter.Get();
+    int32_t xstart = xaxis.IndexOf(rect.x);
+    int32_t xend = xaxis.IndexOf(rect.XMost());
+    int32_t y = yaxis.IndexOf(rect.y);
+    int32_t yend = yaxis.IndexOf(rect.YMost());
+
+    for (; y < yend; y++) {
+      nscoord height = yaxis.StopSize(y);
+      for (int32_t x = xstart; x < xend; x++) {
+        nscoord width = xaxis.StopSize(x);
+        int64_t size = width*int64_t(height);
+        if (rect.Intersects(aContainingRect)) {
+          areas[y*matrixWidth+x].mSizeContainingRect = size;
+        }
+        areas[y*matrixWidth+x].mSize = size;
+      }
+    }
+  }
+
+  // Step 3: Find the maximum submatrix sum that does not contain a rectangle
+  {
+    // First get the prefix sum array
+    int32_t m = matrixHeight + 1;
+    int32_t n = matrixWidth + 1;
+    nsTArray<SizePair> pareas(m*n);
+    pareas.SetLength(m*n);
+    for (int32_t y = 1; y < m; y++) {
+      for (int32_t x = 1; x < n; x++) {
+        SizePair area = areas[(y-1)*matrixWidth+x-1];
+        if (!area.mSize) {
+          area = SizePair::VeryLargeNegative();
+        }
+        area = area + pareas[    y*n+x-1]
+                    + pareas[(y-1)*n+x  ]
+                    - pareas[(y-1)*n+x-1];
+        pareas[y*n+x] = area;
+      }
+    }
+
+    // No longer need the grid
+    areas.SetLength(0);
+
+    SizePair bestArea;
+    struct {
+      int32_t left, top, right, bottom;
+    } bestRectIndices = { 0, 0, 0, 0 };
+    for (int32_t m1 = 0; m1 < m; m1++) {
+      for (int32_t m2 = m1+1; m2 < m; m2++) {
+        nsTArray<SizePair> B;
+        B.SetLength(n);
+        for (int32_t i = 0; i < n; i++) {
+          B[i] = pareas[m2*n+i] - pareas[m1*n+i];
+        }
+        int32_t minIdx, maxIdx;
+        SizePair area = MaxSum1D(B, n, &minIdx, &maxIdx);
+        if (area > bestArea) {
+          bestRectIndices.left = minIdx;
+          bestRectIndices.top = m1;
+          bestRectIndices.right = maxIdx;
+          bestRectIndices.bottom = m2;
+          bestArea = area;
+        }
+      }
+    }
+
+    bestRect.MoveTo(xaxis.StopAt(bestRectIndices.left),
+                    yaxis.StopAt(bestRectIndices.top));
+    bestRect.SizeTo(xaxis.StopAt(bestRectIndices.right) - bestRect.x,
+                    yaxis.StopAt(bestRectIndices.bottom) - bestRect.y);
+  }
+
+  return bestRect;
+}
+
+std::ostream& operator<<(std::ostream& stream, const nsRegion& m) {
+  stream << "[";
+
+  int n;
+  pixman_box32_t *boxes = pixman_region32_rectangles(const_cast<pixman_region32_t*>(&m.mImpl), &n);
+  for (int i=0; i<n; i++) {
+    if (i != 0) {
+      stream << "; ";
+    }
+    stream << boxes[i].x1 << "," << boxes[i].y1 << "," << boxes[i].x2 << "," << boxes[i].y2;
+  }
+
+  stream << "]";
+  return stream;
+}
+
+nsCString
+nsRegion::ToString() const {
+  return nsCString(mozilla::ToString(*this).c_str());
+}
diff --git a/gfx/src/nsRegion.h b/gfx/src/nsRegion.h
new file mode 100644
index 000000000..6f9f7fc8e
--- /dev/null
+++ b/gfx/src/nsRegion.h
@@ -0,0 +1,868 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+
+#ifndef nsRegion_h__
+#define nsRegion_h__
+
+#include <stddef.h>                     // for size_t
+#include <stdint.h>                     // for uint32_t, uint64_t
+#include <sys/types.h>                  // for int32_t
+#include <ostream>                      // for std::ostream
+#include "nsCoord.h"                    // for nscoord
+#include "nsError.h"                    // for nsresult
+#include "nsPoint.h"                    // for nsIntPoint, nsPoint
+#include "nsRect.h"                     // for mozilla::gfx::IntRect, nsRect
+#include "nsMargin.h"                   // for nsIntMargin
+#include "nsRegionFwd.h"                // for nsIntRegion
+#include "nsStringGlue.h"               // for nsCString
+#include "xpcom-config.h"               // for CPP_THROW_NEW
+#include "mozilla/ArrayView.h"          // for ArrayView
+#include "mozilla/Move.h"               // for mozilla::Move
+#include "mozilla/gfx/MatrixFwd.h"      // for mozilla::gfx::Matrix4x4
+
+#include "pixman.h"
+
+/* For information on the internal representation look at pixman-region.c
+ *
+ * This replaces an older homebrew implementation of nsRegion. The
+ * representation used here may use more rectangles than nsRegion however, the
+ * representation is canonical.  This means that there's no need for an
+ * Optimize() method because for a paticular region there is only one
+ * representation. This means that nsIntRegion will have more predictable
+ * performance characteristics than the old nsRegion and should not become
+ * degenerate.
+ *
+ * The pixman region code originates from X11 which has spread to a variety of
+ * projects including Qt, Gtk, Wine. It should perform reasonably well.
+ */
+
+enum class VisitSide {
+	TOP,
+	BOTTOM,
+	LEFT,
+	RIGHT
+};
+
+class nsRegion
+{
+public:
+  typedef nsRect RectType;
+  typedef nsPoint PointType;
+  typedef nsMargin MarginType;
+
+  nsRegion () { pixman_region32_init(&mImpl); }
+  MOZ_IMPLICIT nsRegion (const nsRect& aRect) { pixman_region32_init_rect(&mImpl,
+                                                                          aRect.x,
+                                                                          aRect.y,
+                                                                          aRect.width,
+                                                                          aRect.height); }
+  explicit nsRegion (mozilla::gfx::ArrayView<pixman_box32_t> aRects)
+  {
+    pixman_region32_init_rects(&mImpl, aRects.Data(), aRects.Length());
+  }
+  nsRegion (const nsRegion& aRegion) { pixman_region32_init(&mImpl); pixman_region32_copy(&mImpl,aRegion.Impl()); }
+  nsRegion (nsRegion&& aRegion) { mImpl = aRegion.mImpl; pixman_region32_init(&aRegion.mImpl); }
+  nsRegion& operator = (nsRegion&& aRegion) {
+      pixman_region32_fini(&mImpl);
+      mImpl = aRegion.mImpl;
+      pixman_region32_init(&aRegion.mImpl);
+      return *this;
+  }
+ ~nsRegion () { pixman_region32_fini(&mImpl); }
+  nsRegion& operator = (const nsRect& aRect) { Copy (aRect); return *this; }
+  nsRegion& operator = (const nsRegion& aRegion) { Copy (aRegion); return *this; }
+  bool operator==(const nsRegion& aRgn) const
+  {
+    return IsEqual(aRgn);
+  }
+  bool operator!=(const nsRegion& aRgn) const
+  {
+    return !(*this == aRgn);
+  }
+
+  friend std::ostream& operator<<(std::ostream& stream, const nsRegion& m);
+
+  void Swap(nsRegion* aOther)
+  {
+    pixman_region32_t tmp = mImpl;
+    mImpl = aOther->mImpl;
+    aOther->mImpl = tmp;
+  }
+
+  static
+  nsresult InitStatic()
+  {
+    return NS_OK;
+  }
+
+  static
+  void ShutdownStatic() {}
+
+  void AndWith(const nsRegion& aOther)
+  {
+    And(*this, aOther);
+  }
+  void AndWith(const nsRect& aOther)
+  {
+    And(*this, aOther);
+  }
+  nsRegion& And(const nsRegion& aRgn1,   const nsRegion& aRgn2)
+  {
+    pixman_region32_intersect(&mImpl, aRgn1.Impl(), aRgn2.Impl());
+    return *this;
+  }
+  nsRegion& And(const nsRect& aRect, const nsRegion& aRegion)
+  {
+    return And(aRegion, aRect);
+  }
+  nsRegion& And(const nsRegion& aRegion, const nsRect& aRect)
+  {
+    pixman_region32_intersect_rect(&mImpl, aRegion.Impl(), aRect.x, aRect.y, aRect.width, aRect.height);
+    return *this;
+  }
+  nsRegion& And(const nsRect& aRect1, const nsRect& aRect2)
+  {
+    nsRect TmpRect;
+
+    TmpRect.IntersectRect(aRect1, aRect2);
+    return Copy(TmpRect);
+  }
+
+  nsRegion& OrWith(const nsRegion& aOther)
+  {
+    return Or(*this, aOther);
+  }
+  nsRegion& OrWith(const nsRect& aOther)
+  {
+    return Or(*this, aOther);
+  }
+  nsRegion& Or(const nsRegion& aRgn1, const nsRegion& aRgn2)
+  {
+    pixman_region32_union(&mImpl, aRgn1.Impl(), aRgn2.Impl());
+    return *this;
+  }
+  nsRegion& Or(const nsRegion& aRegion, const nsRect& aRect)
+  {
+    pixman_region32_union_rect(&mImpl, aRegion.Impl(), aRect.x, aRect.y, aRect.width, aRect.height);
+    return *this;
+  }
+  nsRegion& Or(const nsRect& aRect, const nsRegion& aRegion)
+  {
+    return  Or(aRegion, aRect);
+  }
+  nsRegion& Or(const nsRect& aRect1, const nsRect& aRect2)
+  {
+    Copy (aRect1);
+    return Or (*this, aRect2);
+  }
+
+  nsRegion& XorWith(const nsRegion& aOther)
+  {
+    return Xor(*this, aOther);
+  }
+  nsRegion& XorWith(const nsRect& aOther)
+  {
+    return Xor(*this, aOther);
+  }
+  nsRegion& Xor(const nsRegion& aRgn1,   const nsRegion& aRgn2)
+  {
+    // this could be implemented better if pixman had direct
+    // support for xoring regions.
+    nsRegion p;
+    p.Sub(aRgn1, aRgn2);
+    nsRegion q;
+    q.Sub(aRgn2, aRgn1);
+    return Or(p, q);
+  }
+  nsRegion& Xor(const nsRegion& aRegion, const nsRect& aRect)
+  {
+    return Xor(aRegion, nsRegion(aRect));
+  }
+  nsRegion& Xor(const nsRect& aRect, const nsRegion& aRegion)
+  {
+    return Xor(nsRegion(aRect), aRegion);
+  }
+  nsRegion& Xor(const nsRect& aRect1, const nsRect& aRect2)
+  {
+    return Xor(nsRegion(aRect1), nsRegion(aRect2));
+  }
+
+  nsRegion ToAppUnits (nscoord aAppUnitsPerPixel) const;
+
+  nsRegion& SubOut(const nsRegion& aOther)
+  {
+    return Sub(*this, aOther);
+  }
+  nsRegion& SubOut(const nsRect& aOther)
+  {
+    return Sub(*this, aOther);
+  }
+  nsRegion& Sub(const nsRegion& aRgn1, const nsRegion& aRgn2)
+  {
+    pixman_region32_subtract(&mImpl, aRgn1.Impl(), aRgn2.Impl());
+    return *this;
+  }
+  nsRegion& Sub(const nsRegion& aRegion, const nsRect& aRect)
+  {
+    return Sub(aRegion, nsRegion(aRect));
+  }
+  nsRegion& Sub(const nsRect& aRect, const nsRegion& aRegion)
+  {
+    return Sub(nsRegion(aRect), aRegion);
+  }
+  nsRegion& Sub(const nsRect& aRect1, const nsRect& aRect2)
+  {
+    Copy(aRect1);
+    return Sub(*this, aRect2);
+  }
+
+  /**
+   * Returns true iff the given point is inside the region. A region
+   * created from a rect (x=0, y=0, w=100, h=100) will NOT contain
+   * the point x=100, y=100.
+   */
+  bool Contains (int aX, int aY) const
+  {
+    return pixman_region32_contains_point(Impl(), aX, aY, nullptr);
+  }
+  bool Contains (const nsRect& aRect) const
+  {
+    pixman_box32_t box = RectToBox(aRect);
+    return pixman_region32_contains_rectangle(Impl(), &box) == PIXMAN_REGION_IN;
+  }
+  bool Contains (const nsRegion& aRgn) const;
+  bool Intersects (const nsRect& aRect) const;
+
+  void MoveBy (int32_t aXOffset, int32_t aYOffset)
+  {
+    MoveBy (nsPoint (aXOffset, aYOffset));
+  }
+  void MoveBy (nsPoint aPt) { pixman_region32_translate(&mImpl, aPt.x, aPt.y); }
+  void SetEmpty ()
+  {
+    pixman_region32_clear(&mImpl);
+  }
+
+  nsRegion MovedBy(int32_t aXOffset, int32_t aYOffset) const
+  {
+    return MovedBy(nsPoint(aXOffset, aYOffset));
+  }
+  nsRegion MovedBy(const nsPoint& aPt) const
+  {
+    nsRegion copy(*this);
+    copy.MoveBy(aPt);
+    return copy;
+  }
+
+  nsRegion Intersect(const nsRegion& aOther) const
+  {
+    nsRegion intersection;
+    intersection.And(*this, aOther);
+    return intersection;
+  }
+
+  void Inflate(const nsMargin& aMargin);
+
+  nsRegion Inflated(const nsMargin& aMargin) const
+  {
+    nsRegion copy(*this);
+    copy.Inflate(aMargin);
+    return copy;
+  }
+
+  bool IsEmpty () const { return !pixman_region32_not_empty(Impl()); }
+  bool IsComplex () const { return GetNumRects() > 1; }
+  bool IsEqual (const nsRegion& aRegion) const
+  {
+    return pixman_region32_equal(Impl(), aRegion.Impl());
+  }
+  uint32_t GetNumRects () const
+  {
+    // Work around pixman bug. Sometimes pixman creates regions with 1 rect
+    // that's empty.
+    uint32_t result = pixman_region32_n_rects(Impl());
+    return (result == 1 && GetBounds().IsEmpty()) ? 0 : result;
+  }
+  const nsRect GetBounds () const { return BoxToRect(mImpl.extents); }
+  uint64_t Area () const;
+
+  /**
+   * Return this region scaled to a different appunits per pixel (APP) ratio.
+   * This applies nsRect::ScaleToOtherAppUnitsRoundOut/In to each rect of the region.
+   * @param aFromAPP the APP to scale from
+   * @param aToAPP the APP to scale to
+   * @note this can turn an empty region into a non-empty region
+   */
+  MOZ_MUST_USE nsRegion
+    ScaleToOtherAppUnitsRoundOut (int32_t aFromAPP, int32_t aToAPP) const;
+  MOZ_MUST_USE nsRegion
+    ScaleToOtherAppUnitsRoundIn (int32_t aFromAPP, int32_t aToAPP) const;
+  nsRegion& ScaleRoundOut(float aXScale, float aYScale);
+  nsRegion& ScaleInverseRoundOut(float aXScale, float aYScale);
+  nsRegion& Transform (const mozilla::gfx::Matrix4x4 &aTransform);
+  nsIntRegion ScaleToOutsidePixels (float aXScale, float aYScale, nscoord aAppUnitsPerPixel) const;
+  nsIntRegion ScaleToInsidePixels (float aXScale, float aYScale, nscoord aAppUnitsPerPixel) const;
+  nsIntRegion ScaleToNearestPixels (float aXScale, float aYScale, nscoord aAppUnitsPerPixel) const;
+  nsIntRegion ToOutsidePixels (nscoord aAppUnitsPerPixel) const;
+  nsIntRegion ToNearestPixels (nscoord aAppUnitsPerPixel) const;
+
+  /**
+   * Gets the largest rectangle contained in the region.
+   * @param aContainingRect if non-empty, we choose a rectangle that
+   * maximizes the area intersecting with aContainingRect (and break ties by
+   * then choosing the largest rectangle overall)
+   */
+  nsRect GetLargestRectangle (const nsRect& aContainingRect = nsRect()) const;
+
+  /**
+   * Make sure the region has at most aMaxRects by adding area to it
+   * if necessary. The simplified region will be a superset of the
+   * original region. The simplified region's bounding box will be
+   * the same as for the current region.
+   */
+  void SimplifyOutward (uint32_t aMaxRects);
+  /**
+   * Simplify the region by adding at most aThreshold area between spans of
+   * rects.  The simplified region will be a superset of the original region.
+   * The simplified region's bounding box will be the same as for the current
+   * region.
+   */
+  void SimplifyOutwardByArea(uint32_t aThreshold);
+  /**
+   * Make sure the region has at most aMaxRects by removing area from
+   * it if necessary. The simplified region will be a subset of the
+   * original region.
+   */
+  void SimplifyInward (uint32_t aMaxRects);
+
+  /**
+   * VisitEdges is a weird kind of function that we use for padding
+   * out surfaces to prevent texture filtering artifacts.
+   * It calls the visitFn callback for each of the exterior edges of
+   * the regions. The top and bottom edges will be expanded 1 pixel
+   * to the left and right if there's an outside corner. The order
+   * the edges are visited is not guaranteed.
+   *
+   * visitFn has a side parameter that can be TOP,BOTTOM,LEFT,RIGHT
+   * and specifies which kind of edge is being visited. x1, y1, x2, y2
+   * are the coordinates of the line. (x1 == x2) || (y1 == y2)
+   */
+  typedef void (*visitFn)(void *closure, VisitSide side, int x1, int y1, int x2, int y2);
+  void VisitEdges(visitFn, void *closure);
+
+  nsCString ToString() const;
+
+  class RectIterator
+  {
+    int mCurrent;               // Index of the current entry
+    int mLimit;                 // Index one past the final entry.
+    mutable nsRect mTmp;        // The most recently gotten rectangle.
+    pixman_box32_t *mBoxes;
+
+  public:
+    explicit RectIterator(const nsRegion& aRegion)
+    {
+      mCurrent = 0;
+      mBoxes = pixman_region32_rectangles(aRegion.Impl(), &mLimit);
+      // Work around pixman bug. Sometimes pixman creates regions with 1 rect
+      // that's empty.
+      if (mLimit == 1 && nsRegion::BoxToRect(mBoxes[0]).IsEmpty()) {
+        mLimit = 0;
+      }
+    }
+
+    bool Done() const { return mCurrent == mLimit; }
+
+    const nsRect& Get() const
+    {
+      MOZ_ASSERT(!Done());
+      mTmp = nsRegion::BoxToRect(mBoxes[mCurrent]);
+      NS_ASSERTION(!mTmp.IsEmpty(), "Shouldn't return empty rect");
+      return mTmp;
+    }
+
+    void Next()
+    {
+      MOZ_ASSERT(!Done());
+      mCurrent++;
+    }
+  };
+
+  RectIterator RectIter() const { return RectIterator(*this); }
+
+private:
+  pixman_region32_t mImpl;
+
+#ifndef MOZ_TREE_PIXMAN
+  // For compatibility with pixman versions older than 0.25.2.
+  static inline void
+  pixman_region32_clear(pixman_region32_t *region)
+  {
+    pixman_region32_fini(region);
+    pixman_region32_init(region);
+  }
+#endif
+
+  nsIntRegion ToPixels(nscoord aAppUnitsPerPixel, bool aOutsidePixels) const;
+
+  nsRegion& Copy (const nsRegion& aRegion)
+  {
+    pixman_region32_copy(&mImpl, aRegion.Impl());
+    return *this;
+  }
+
+  nsRegion& Copy (const nsRect& aRect)
+  {
+    // pixman needs to distinguish between an empty region and a region
+    // with one rect so that it can return a different number of rectangles.
+    // Empty rect: data = empty_box
+    //     1 rect: data = null
+    //    >1 rect: data = rects
+    if (aRect.IsEmpty()) {
+      pixman_region32_clear(&mImpl);
+    } else {
+      pixman_box32_t box = RectToBox(aRect);
+      pixman_region32_reset(&mImpl, &box);
+    }
+    return *this;
+  }
+
+  static inline pixman_box32_t RectToBox(const nsRect &aRect)
+  {
+    pixman_box32_t box = { aRect.x, aRect.y, aRect.XMost(), aRect.YMost() };
+    return box;
+  }
+
+  static inline pixman_box32_t RectToBox(const mozilla::gfx::IntRect &aRect)
+  {
+    pixman_box32_t box = { aRect.x, aRect.y, aRect.XMost(), aRect.YMost() };
+    return box;
+  }
+
+
+  static inline nsRect BoxToRect(const pixman_box32_t &aBox)
+  {
+    return nsRect(aBox.x1, aBox.y1,
+                  aBox.x2 - aBox.x1,
+                  aBox.y2 - aBox.y1);
+  }
+
+  pixman_region32_t* Impl() const
+  {
+    return const_cast<pixman_region32_t*>(&mImpl);
+  }
+};
+
+namespace mozilla {
+namespace gfx {
+
+/**
+ * BaseIntRegions use int32_t coordinates.
+ */
+template <typename Derived, typename Rect, typename Point, typename Margin>
+class BaseIntRegion
+{
+  friend class ::nsRegion;
+
+  // Give access to all specializations of IntRegionTyped, not just ones that
+  // derive from this specialization of BaseIntRegion.
+  template <typename units>
+  friend class IntRegionTyped;
+
+public:
+  typedef Rect RectType;
+  typedef Point PointType;
+  typedef Margin MarginType;
+
+  BaseIntRegion () {}
+  MOZ_IMPLICIT BaseIntRegion (const Rect& aRect) : mImpl (ToRect(aRect)) {}
+  explicit BaseIntRegion (mozilla::gfx::ArrayView<pixman_box32_t> aRects) : mImpl (aRects) {}
+  BaseIntRegion (const BaseIntRegion& aRegion) : mImpl (aRegion.mImpl) {}
+  BaseIntRegion (BaseIntRegion&& aRegion) : mImpl (mozilla::Move(aRegion.mImpl)) {}
+  Derived& operator = (const Rect& aRect) { mImpl = ToRect (aRect); return This(); }
+  Derived& operator = (const Derived& aRegion) { mImpl = aRegion.mImpl; return This(); }
+  Derived& operator = (Derived&& aRegion) { mImpl = mozilla::Move(aRegion.mImpl); return This(); }
+
+  bool operator==(const Derived& aRgn) const
+  {
+    return IsEqual(aRgn);
+  }
+  bool operator!=(const Derived& aRgn) const
+  {
+    return !(*this == aRgn);
+  }
+
+  friend std::ostream& operator<<(std::ostream& stream, const Derived& m) {
+    return stream << m.mImpl;
+  }
+
+  void Swap(Derived* aOther)
+  {
+    mImpl.Swap(&aOther->mImpl);
+  }
+
+  void AndWith(const Derived& aOther)
+  {
+    And(This(), aOther);
+  }
+  void AndWith(const Rect& aOther)
+  {
+    And(This(), aOther);
+  }
+  Derived& And  (const Derived& aRgn1,   const Derived& aRgn2)
+  {
+    mImpl.And (aRgn1.mImpl, aRgn2.mImpl);
+    return This();
+  }
+  Derived& And  (const Derived& aRegion, const Rect& aRect)
+  {
+    mImpl.And (aRegion.mImpl, ToRect (aRect));
+    return This();
+  }
+  Derived& And  (const Rect& aRect, const Derived& aRegion)
+  {
+    return  And  (aRegion, aRect);
+  }
+  Derived& And  (const Rect& aRect1, const Rect& aRect2)
+  {
+    Rect TmpRect;
+
+    TmpRect.IntersectRect (aRect1, aRect2);
+    mImpl = ToRect (TmpRect);
+    return This();
+  }
+
+  Derived& OrWith(const Derived& aOther)
+  {
+    return Or(This(), aOther);
+  }
+  Derived& OrWith(const Rect& aOther)
+  {
+    return Or(This(), aOther);
+  }
+  Derived& Or   (const Derived& aRgn1,   const Derived& aRgn2)
+  {
+    mImpl.Or (aRgn1.mImpl, aRgn2.mImpl);
+    return This();
+  }
+  Derived& Or   (const Derived& aRegion, const Rect& aRect)
+  {
+    mImpl.Or (aRegion.mImpl, ToRect (aRect));
+    return This();
+  }
+  Derived& Or   (const Rect& aRect, const Derived& aRegion)
+  {
+    return  Or   (aRegion, aRect);
+  }
+  Derived& Or   (const Rect& aRect1, const Rect& aRect2)
+  {
+    mImpl = ToRect (aRect1);
+    return Or (This(), aRect2);
+  }
+
+  Derived& XorWith(const Derived& aOther)
+  {
+    return Xor(This(), aOther);
+  }
+  Derived& XorWith(const Rect& aOther)
+  {
+    return Xor(This(), aOther);
+  }
+  Derived& Xor  (const Derived& aRgn1,   const Derived& aRgn2)
+  {
+    mImpl.Xor (aRgn1.mImpl, aRgn2.mImpl);
+    return This();
+  }
+  Derived& Xor  (const Derived& aRegion, const Rect& aRect)
+  {
+    mImpl.Xor (aRegion.mImpl, ToRect (aRect));
+    return This();
+  }
+  Derived& Xor  (const Rect& aRect, const Derived& aRegion)
+  {
+    return  Xor  (aRegion, aRect);
+  }
+  Derived& Xor  (const Rect& aRect1, const Rect& aRect2)
+  {
+    mImpl = ToRect (aRect1);
+    return Xor (This(), aRect2);
+  }
+
+  Derived& SubOut(const Derived& aOther)
+  {
+    return Sub(This(), aOther);
+  }
+  Derived& SubOut(const Rect& aOther)
+  {
+    return Sub(This(), aOther);
+  }
+  Derived& Sub  (const Derived& aRgn1,   const Derived& aRgn2)
+  {
+    mImpl.Sub (aRgn1.mImpl, aRgn2.mImpl);
+    return This();
+  }
+  Derived& Sub  (const Derived& aRegion, const Rect& aRect)
+  {
+    mImpl.Sub (aRegion.mImpl, ToRect (aRect));
+    return This();
+  }
+  Derived& Sub  (const Rect& aRect, const Derived& aRegion)
+  {
+    return Sub (Derived (aRect), aRegion);
+  }
+  Derived& Sub  (const Rect& aRect1, const Rect& aRect2)
+  {
+    mImpl = ToRect (aRect1);
+    return Sub (This(), aRect2);
+  }
+
+  /**
+   * Returns true iff the given point is inside the region. A region
+   * created from a rect (x=0, y=0, w=100, h=100) will NOT contain
+   * the point x=100, y=100.
+   */
+  bool Contains (int aX, int aY) const
+  {
+    return mImpl.Contains(aX, aY);
+  }
+  bool Contains (const Rect& aRect) const
+  {
+    return mImpl.Contains (ToRect (aRect));
+  }
+  bool Contains (const Derived& aRgn) const
+  {
+    return mImpl.Contains (aRgn.mImpl);
+  }
+  bool Intersects (const Rect& aRect) const
+  {
+    return mImpl.Intersects (ToRect (aRect));
+  }
+
+  void MoveBy (int32_t aXOffset, int32_t aYOffset)
+  {
+    MoveBy (Point (aXOffset, aYOffset));
+  }
+  void MoveBy (Point aPt)
+  {
+    mImpl.MoveBy (aPt.x, aPt.y);
+  }
+  Derived MovedBy(int32_t aXOffset, int32_t aYOffset) const
+  {
+    return MovedBy(Point(aXOffset, aYOffset));
+  }
+  Derived MovedBy(const Point& aPt) const
+  {
+    Derived copy(This());
+    copy.MoveBy(aPt);
+    return copy;
+  }
+
+  Derived Intersect(const Derived& aOther) const
+  {
+    Derived intersection;
+    intersection.And(This(), aOther);
+    return intersection;
+  }
+
+  void Inflate(const Margin& aMargin)
+  {
+    mImpl.Inflate(nsMargin(aMargin.top, aMargin.right, aMargin.bottom, aMargin.left));
+  }
+  Derived Inflated(const Margin& aMargin) const
+  {
+    Derived copy(This());
+    copy.Inflate(aMargin);
+    return copy;
+  }
+
+  void SetEmpty ()
+  {
+    mImpl.SetEmpty  ();
+  }
+
+  bool IsEmpty () const { return mImpl.IsEmpty (); }
+  bool IsComplex () const { return mImpl.IsComplex (); }
+  bool IsEqual (const Derived& aRegion) const
+  {
+    return mImpl.IsEqual (aRegion.mImpl);
+  }
+  uint32_t GetNumRects () const { return mImpl.GetNumRects (); }
+  Rect GetBounds () const { return FromRect (mImpl.GetBounds ()); }
+  uint64_t Area () const { return mImpl.Area(); }
+  nsRegion ToAppUnits (nscoord aAppUnitsPerPixel) const
+  {
+    nsRegion result;
+    for (auto iter = RectIter(); !iter.Done(); iter.Next()) {
+      nsRect appRect = ::ToAppUnits(iter.Get(), aAppUnitsPerPixel);
+      result.Or(result, appRect);
+    }
+    return result;
+  }
+  Rect GetLargestRectangle (const Rect& aContainingRect = Rect()) const
+  {
+    return FromRect (mImpl.GetLargestRectangle( ToRect(aContainingRect) ));
+  }
+
+  Derived& ScaleRoundOut (float aXScale, float aYScale)
+  {
+    mImpl.ScaleRoundOut(aXScale, aYScale);
+    return This();
+  }
+
+  Derived& ScaleInverseRoundOut (float aXScale, float aYScale)
+  {
+    mImpl.ScaleInverseRoundOut(aXScale, aYScale);
+    return This();
+  }
+
+  // Prefer using TransformBy(matrix, region) from UnitTransforms.h,
+  // as applying the transform should typically change the unit system.
+  // TODO(botond): Move this to IntRegionTyped and disable it for
+  //               unit != UnknownUnits.
+  Derived& Transform (const mozilla::gfx::Matrix4x4 &aTransform)
+  {
+    mImpl.Transform(aTransform);
+    return This();
+  }
+
+  /**
+   * Make sure the region has at most aMaxRects by adding area to it
+   * if necessary. The simplified region will be a superset of the
+   * original region. The simplified region's bounding box will be
+   * the same as for the current region.
+   */
+  void SimplifyOutward (uint32_t aMaxRects)
+  {
+    mImpl.SimplifyOutward (aMaxRects);
+  }
+  void SimplifyOutwardByArea (uint32_t aThreshold)
+  {
+    mImpl.SimplifyOutwardByArea (aThreshold);
+  }
+  /**
+   * Make sure the region has at most aMaxRects by removing area from
+   * it if necessary. The simplified region will be a subset of the
+   * original region.
+   */
+  void SimplifyInward (uint32_t aMaxRects)
+  {
+    mImpl.SimplifyInward (aMaxRects);
+  }
+
+  typedef void (*visitFn)(void *closure, VisitSide side, int x1, int y1, int x2, int y2);
+  void VisitEdges (visitFn visit, void *closure)
+  {
+    mImpl.VisitEdges (visit, closure);
+  }
+
+  nsCString ToString() const { return mImpl.ToString(); }
+
+  class RectIterator
+  {
+    nsRegion::RectIterator mImpl; // The underlying iterator.
+    mutable Rect mTmp;            // The most recently gotten rectangle.
+
+  public:
+    explicit RectIterator(const BaseIntRegion& aRegion)
+      : mImpl(aRegion.mImpl)
+    {}
+
+    bool Done() const { return mImpl.Done(); }
+
+    const Rect& Get() const
+    {
+      mTmp = FromRect(mImpl.Get());
+      return mTmp;
+    }
+
+    void Next() { mImpl.Next(); }
+  };
+
+  RectIterator RectIter() const { return RectIterator(*this); }
+
+protected:
+  // Expose enough to derived classes from them to define conversions
+  // between different types of BaseIntRegions.
+  explicit BaseIntRegion(const nsRegion& aImpl) : mImpl(aImpl) {}
+  const nsRegion& Impl() const { return mImpl; }
+private:
+  nsRegion mImpl;
+
+  static nsRect ToRect(const Rect& aRect)
+  {
+    return nsRect (aRect.x, aRect.y, aRect.width, aRect.height);
+  }
+  static Rect FromRect(const nsRect& aRect)
+  {
+    return Rect (aRect.x, aRect.y, aRect.width, aRect.height);
+  }
+
+  Derived& This()
+  {
+    return *static_cast<Derived*>(this);
+  }
+  const Derived& This() const
+  {
+    return *static_cast<const Derived*>(this);
+  }
+};
+
+template <class units>
+class IntRegionTyped :
+    public BaseIntRegion<IntRegionTyped<units>, IntRectTyped<units>, IntPointTyped<units>, IntMarginTyped<units>>
+{
+  typedef BaseIntRegion<IntRegionTyped<units>, IntRectTyped<units>, IntPointTyped<units>, IntMarginTyped<units>> Super;
+
+  // Make other specializations of IntRegionTyped friends.
+  template <typename OtherUnits>
+  friend class IntRegionTyped;
+
+  static_assert(IsPixel<units>::value, "'units' must be a coordinate system tag");
+
+public:
+  typedef IntRectTyped<units> RectType;
+  typedef IntPointTyped<units> PointType;
+  typedef IntMarginTyped<units> MarginType;
+
+  // Forward constructors.
+  IntRegionTyped() {}
+  MOZ_IMPLICIT IntRegionTyped(const IntRectTyped<units>& aRect) : Super(aRect) {}
+  IntRegionTyped(const IntRegionTyped& aRegion) : Super(aRegion) {}
+  explicit IntRegionTyped(mozilla::gfx::ArrayView<pixman_box32_t> aRects) : Super(aRects) {}
+  IntRegionTyped(IntRegionTyped&& aRegion) : Super(mozilla::Move(aRegion)) {}
+
+  // Assignment operators need to be forwarded as well, otherwise the compiler
+  // will declare deleted ones.
+  IntRegionTyped& operator=(const IntRegionTyped& aRegion)
+  {
+    return Super::operator=(aRegion);
+  }
+  IntRegionTyped& operator=(IntRegionTyped&& aRegion)
+  {
+    return Super::operator=(mozilla::Move(aRegion));
+  }
+
+  static IntRegionTyped FromUnknownRegion(const IntRegion& aRegion)
+  {
+    return IntRegionTyped(aRegion.Impl());
+  }
+  IntRegion ToUnknownRegion() const
+  {
+    // Need |this->| because Impl() is defined in a dependent base class.
+    return IntRegion(this->Impl());
+  }
+private:
+  // This is deliberately private, so calling code uses FromUnknownRegion().
+  explicit IntRegionTyped(const nsRegion& aRegion) : Super(aRegion) {}
+};
+
+} // namespace gfx
+} // namespace mozilla
+
+typedef mozilla::gfx::IntRegion nsIntRegion;
+
+#endif
diff --git a/gfx/src/nsRegionFwd.h b/gfx/src/nsRegionFwd.h
new file mode 100644
index 000000000..6d5345d14
--- /dev/null
+++ b/gfx/src/nsRegionFwd.h
@@ -0,0 +1,26 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+
+#ifndef nsRegionFwd_h__
+#define nsRegionFwd_h__
+
+// Forward declare enough things to define the typedef |nsIntRegion|.
+
+namespace mozilla {
+namespace gfx {
+
+struct UnknownUnits;
+
+template <class units>
+class IntRegionTyped;
+
+typedef IntRegionTyped<UnknownUnits> IntRegion;
+
+} // namespace gfx
+} // namespace mozilla
+
+typedef mozilla::gfx::IntRegion nsIntRegion;
+
+#endif
diff --git a/gfx/src/nsRenderingContext.h b/gfx/src/nsRenderingContext.h
new file mode 100644
index 000000000..02bb397d6
--- /dev/null
+++ b/gfx/src/nsRenderingContext.h
@@ -0,0 +1,41 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef NSRENDERINGCONTEXT__H__
+#define NSRENDERINGCONTEXT__H__
+
+#include "gfxContext.h"
+#include "mozilla/Attributes.h"
+#include "nsCOMPtr.h"
+#include "mozilla/RefPtr.h"
+
+namespace mozilla {
+namespace gfx {
+class DrawTarget;
+} // namespace gfx
+} // namespace mozilla
+
+class MOZ_STACK_CLASS nsRenderingContext final
+{
+    typedef mozilla::gfx::DrawTarget DrawTarget;
+
+public:
+    explicit nsRenderingContext(gfxContext* aThebesContext)
+      : mThebes(aThebesContext)
+    {}
+
+    explicit nsRenderingContext(already_AddRefed<gfxContext>&& aThebesContext)
+      : mThebes(aThebesContext)
+    {}
+
+    // These accessors will never return null.
+    gfxContext *ThebesContext() { return mThebes; }
+    DrawTarget *GetDrawTarget() { return mThebes->GetDrawTarget(); }
+
+private:
+    RefPtr<gfxContext> mThebes;
+};
+
+#endif  // NSRENDERINGCONTEXT__H__
diff --git a/gfx/src/nsScriptableRegion.cpp b/gfx/src/nsScriptableRegion.cpp
new file mode 100644
index 000000000..f0afff8f4
--- /dev/null
+++ b/gfx/src/nsScriptableRegion.cpp
@@ -0,0 +1,159 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsScriptableRegion.h"
+#include <stdint.h>                     // for uint32_t
+#include <sys/types.h>                  // for int32_t
+#include "js/RootingAPI.h"              // for Rooted
+#include "js/Value.h"                   // for INT_TO_JSVAL, etc
+#include "jsapi.h"                      // for JS_DefineElement, etc
+#include "mozilla/Assertions.h"         // for MOZ_ASSERT_HELPER2
+#include "nsError.h"                    // for NS_OK, NS_ERROR_FAILURE, etc
+#include "nsID.h"
+#include "nsRect.h"                     // for mozilla::gfx::IntRect
+#include "nscore.h"                     // for NS_IMETHODIMP
+
+class JSObject;
+struct JSContext;
+
+nsScriptableRegion::nsScriptableRegion()
+{
+}
+
+NS_IMPL_ISUPPORTS(nsScriptableRegion, nsIScriptableRegion)
+
+NS_IMETHODIMP nsScriptableRegion::Init()
+{
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsScriptableRegion::SetToRegion(nsIScriptableRegion *aRegion)
+{
+  aRegion->GetRegion(&mRegion);
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsScriptableRegion::SetToRect(int32_t aX, int32_t aY, int32_t aWidth, int32_t aHeight)
+{
+  mRegion = mozilla::gfx::IntRect(aX, aY, aWidth, aHeight);
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsScriptableRegion::IntersectRegion(nsIScriptableRegion *aRegion)
+{
+  nsIntRegion region;
+  aRegion->GetRegion(&region);
+  mRegion.And(mRegion, region);
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsScriptableRegion::IntersectRect(int32_t aX, int32_t aY, int32_t aWidth, int32_t aHeight)
+{
+  mRegion.And(mRegion, mozilla::gfx::IntRect(aX, aY, aWidth, aHeight));
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsScriptableRegion::UnionRegion(nsIScriptableRegion *aRegion)
+{
+  nsIntRegion region;
+  aRegion->GetRegion(&region);
+  mRegion.Or(mRegion, region);
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsScriptableRegion::UnionRect(int32_t aX, int32_t aY, int32_t aWidth, int32_t aHeight)
+{
+  mRegion.Or(mRegion, mozilla::gfx::IntRect(aX, aY, aWidth, aHeight));
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsScriptableRegion::SubtractRegion(nsIScriptableRegion *aRegion)
+{
+  nsIntRegion region;
+  aRegion->GetRegion(&region);
+  mRegion.Sub(mRegion, region);
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsScriptableRegion::SubtractRect(int32_t aX, int32_t aY, int32_t aWidth, int32_t aHeight)
+{
+  mRegion.Sub(mRegion, mozilla::gfx::IntRect(aX, aY, aWidth, aHeight));
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsScriptableRegion::IsEmpty(bool *isEmpty)
+{
+  *isEmpty = mRegion.IsEmpty();
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsScriptableRegion::IsEqualRegion(nsIScriptableRegion *aRegion, bool *isEqual)
+{
+  nsIntRegion region;
+  aRegion->GetRegion(&region);
+  *isEqual = mRegion.IsEqual(region);
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsScriptableRegion::GetBoundingBox(int32_t *aX, int32_t *aY, int32_t *aWidth, int32_t *aHeight)
+{
+  mozilla::gfx::IntRect boundRect = mRegion.GetBounds();
+  *aX = boundRect.x;
+  *aY = boundRect.y;
+  *aWidth = boundRect.width;
+  *aHeight = boundRect.height;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsScriptableRegion::Offset(int32_t aXOffset, int32_t aYOffset)
+{
+  mRegion.MoveBy(aXOffset, aYOffset);
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsScriptableRegion::ContainsRect(int32_t aX, int32_t aY, int32_t aWidth, int32_t aHeight, bool *containsRect)
+{
+  *containsRect = mRegion.Contains(mozilla::gfx::IntRect(aX, aY, aWidth, aHeight));
+  return NS_OK;
+}
+
+
+NS_IMETHODIMP nsScriptableRegion::GetRegion(nsIntRegion* outRgn)
+{
+  *outRgn = mRegion;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsScriptableRegion::GetRects(JSContext* aCx, JS::MutableHandle<JS::Value> aRects)
+{
+  uint32_t numRects = mRegion.GetNumRects();
+
+  if (!numRects) {
+    aRects.setNull();
+    return NS_OK;
+  }
+
+  JS::Rooted<JSObject*> destArray(aCx, JS_NewArrayObject(aCx, numRects * 4));
+  if (!destArray) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  aRects.setObject(*destArray);
+
+  uint32_t n = 0;
+  for (auto iter = mRegion.RectIter(); !iter.Done(); iter.Next()) {
+    const mozilla::gfx::IntRect& rect = iter.Get();
+    if (!JS_DefineElement(aCx, destArray, n, rect.x, JSPROP_ENUMERATE) ||
+        !JS_DefineElement(aCx, destArray, n + 1, rect.y, JSPROP_ENUMERATE) ||
+        !JS_DefineElement(aCx, destArray, n + 2, rect.width, JSPROP_ENUMERATE) ||
+        !JS_DefineElement(aCx, destArray, n + 3, rect.height, JSPROP_ENUMERATE)) {
+      return NS_ERROR_FAILURE;
+    }
+    n += 4;
+  }
+
+  return NS_OK;
+}
diff --git a/gfx/src/nsScriptableRegion.h b/gfx/src/nsScriptableRegion.h
new file mode 100644
index 000000000..094093c75
--- /dev/null
+++ b/gfx/src/nsScriptableRegion.h
@@ -0,0 +1,28 @@
+/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsScriptableRegion_h
+#define nsScriptableRegion_h
+
+#include "nsIScriptableRegion.h"
+#include "nsISupports.h"
+#include "nsRegion.h"
+#include "mozilla/Attributes.h"
+
+class nsScriptableRegion final : public nsIScriptableRegion {
+public:
+	nsScriptableRegion();
+
+	NS_DECL_ISUPPORTS
+
+	NS_DECL_NSISCRIPTABLEREGION
+
+private:
+        ~nsScriptableRegion() {}
+	nsIntRegion mRegion;
+};
+
+#endif
diff --git a/gfx/src/nsSize.h b/gfx/src/nsSize.h
new file mode 100644
index 000000000..f27c478f9
--- /dev/null
+++ b/gfx/src/nsSize.h
@@ -0,0 +1,70 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef NSSIZE_H
+#define NSSIZE_H
+
+#include "nsCoord.h"
+#include "mozilla/gfx/BaseSize.h"
+#include "mozilla/gfx/Point.h"
+
+// Maximum allowable size
+#define NS_MAXSIZE nscoord_MAX
+
+typedef mozilla::gfx::IntSize nsIntSize;
+
+struct nsSize : public mozilla::gfx::BaseSize<nscoord, nsSize> {
+  typedef mozilla::gfx::BaseSize<nscoord, nsSize> Super;
+
+  nsSize() : Super() {}
+  nsSize(nscoord aWidth, nscoord aHeight) : Super(aWidth, aHeight) {}
+
+  inline mozilla::gfx::IntSize ScaleToNearestPixels(float aXScale, float aYScale,
+                                        nscoord aAppUnitsPerPixel) const;
+  inline mozilla::gfx::IntSize ToNearestPixels(nscoord aAppUnitsPerPixel) const;
+
+  /**
+   * Return this size scaled to a different appunits per pixel (APP) ratio.
+   * @param aFromAPP the APP to scale from
+   * @param aToAPP the APP to scale to
+   */
+  MOZ_MUST_USE inline nsSize
+    ScaleToOtherAppUnits(int32_t aFromAPP, int32_t aToAPP) const;
+};
+
+inline mozilla::gfx::IntSize
+nsSize::ScaleToNearestPixels(float aXScale, float aYScale,
+                             nscoord aAppUnitsPerPixel) const
+{
+  return mozilla::gfx::IntSize(
+      NSToIntRoundUp(NSAppUnitsToDoublePixels(width, aAppUnitsPerPixel) * aXScale),
+      NSToIntRoundUp(NSAppUnitsToDoublePixels(height, aAppUnitsPerPixel) * aYScale));
+}
+
+inline mozilla::gfx::IntSize
+nsSize::ToNearestPixels(nscoord aAppUnitsPerPixel) const
+{
+  return ScaleToNearestPixels(1.0f, 1.0f, aAppUnitsPerPixel);
+}
+
+inline nsSize
+nsSize::ScaleToOtherAppUnits(int32_t aFromAPP, int32_t aToAPP) const {
+  if (aFromAPP != aToAPP) {
+    nsSize size;
+    size.width = NSToCoordRound(NSCoordScale(width, aFromAPP, aToAPP));
+    size.height = NSToCoordRound(NSCoordScale(height, aFromAPP, aToAPP));
+    return size;
+  }
+  return *this;
+}
+
+inline nsSize
+IntSizeToAppUnits(mozilla::gfx::IntSize aSize, nscoord aAppUnitsPerPixel)
+{
+  return nsSize(NSIntPixelsToAppUnits(aSize.width, aAppUnitsPerPixel),
+                NSIntPixelsToAppUnits(aSize.height, aAppUnitsPerPixel));
+}
+
+#endif /* NSSIZE_H */
diff --git a/gfx/src/nsThebesFontEnumerator.cpp b/gfx/src/nsThebesFontEnumerator.cpp
new file mode 100644
index 000000000..3ef3f443b
--- /dev/null
+++ b/gfx/src/nsThebesFontEnumerator.cpp
@@ -0,0 +1,129 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsThebesFontEnumerator.h"
+#include <stdint.h>                     // for uint32_t
+#include "gfxPlatform.h"                // for gfxPlatform
+#include "mozilla/Assertions.h"         // for MOZ_ASSERT_HELPER2
+#include "nsCOMPtr.h"                   // for nsCOMPtr
+#include "nsDebug.h"                    // for NS_ENSURE_ARG_POINTER
+#include "nsError.h"                    // for NS_OK, NS_FAILED, nsresult
+#include "nsIAtom.h"                    // for nsIAtom, NS_Atomize
+#include "nsID.h"
+#include "nsMemory.h"                   // for nsMemory
+#include "nsString.h"               // for nsAutoCString, nsAutoString, etc
+#include "nsTArray.h"                   // for nsTArray, nsTArray_Impl, etc
+#include "nscore.h"                     // for char16_t, NS_IMETHODIMP
+
+NS_IMPL_ISUPPORTS(nsThebesFontEnumerator, nsIFontEnumerator)
+
+nsThebesFontEnumerator::nsThebesFontEnumerator()
+{
+}
+
+NS_IMETHODIMP
+nsThebesFontEnumerator::EnumerateAllFonts(uint32_t *aCount,
+                                          char16_t ***aResult)
+{
+    return EnumerateFonts (nullptr, nullptr, aCount, aResult);
+}
+
+NS_IMETHODIMP
+nsThebesFontEnumerator::EnumerateFonts(const char *aLangGroup,
+                                       const char *aGeneric,
+                                       uint32_t *aCount,
+                                       char16_t ***aResult)
+{
+    NS_ENSURE_ARG_POINTER(aCount);
+    NS_ENSURE_ARG_POINTER(aResult);
+
+    nsTArray<nsString> fontList;
+
+    nsAutoCString generic;
+    if (aGeneric)
+        generic.Assign(aGeneric);
+    else
+        generic.SetIsVoid(true);
+
+    nsCOMPtr<nsIAtom> langGroupAtom;
+    if (aLangGroup) {
+        nsAutoCString lowered;
+        lowered.Assign(aLangGroup);
+        ToLowerCase(lowered);
+        langGroupAtom = NS_Atomize(lowered);
+    }
+
+    nsresult rv = gfxPlatform::GetPlatform()->GetFontList(langGroupAtom, generic, fontList);
+
+    if (NS_FAILED(rv)) {
+        *aCount = 0;
+        *aResult = nullptr;
+        /* XXX in this case, do we want to return the CSS generics? */
+        return NS_OK;
+    }
+
+    char16_t **fs = static_cast<char16_t **>
+                                (moz_xmalloc(fontList.Length() * sizeof(char16_t*)));
+    for (uint32_t i = 0; i < fontList.Length(); i++) {
+        fs[i] = ToNewUnicode(fontList[i]);
+    }
+
+    *aResult = fs;
+    *aCount = fontList.Length();
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsThebesFontEnumerator::HaveFontFor(const char *aLangGroup,
+                                    bool *aResult)
+{
+    NS_ENSURE_ARG_POINTER(aResult);
+
+    *aResult = true;
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsThebesFontEnumerator::GetDefaultFont(const char *aLangGroup,
+                                       const char *aGeneric,
+                                       char16_t **aResult)
+{
+    NS_ENSURE_ARG_POINTER(aResult);
+    *aResult = nullptr;
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsThebesFontEnumerator::UpdateFontList(bool *_retval)
+{
+    gfxPlatform::GetPlatform()->UpdateFontList();
+    *_retval = false; // always return false for now
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsThebesFontEnumerator::GetStandardFamilyName(const char16_t *aName,
+                                              char16_t **aResult)
+{
+    NS_ENSURE_ARG_POINTER(aResult);
+    NS_ENSURE_ARG_POINTER(aName);
+
+    nsAutoString name(aName);
+    if (name.IsEmpty()) {
+        *aResult = nullptr;
+        return NS_OK;
+    }
+
+    nsAutoString family;
+    nsresult rv = gfxPlatform::GetPlatform()->
+        GetStandardFamilyName(nsDependentString(aName), family);
+    if (NS_FAILED(rv) || family.IsEmpty()) {
+        *aResult = nullptr;
+        return NS_OK;
+    }
+    *aResult = ToNewUnicode(family);
+    return NS_OK;
+}
diff --git a/gfx/src/nsThebesFontEnumerator.h b/gfx/src/nsThebesFontEnumerator.h
new file mode 100644
index 000000000..666663e3a
--- /dev/null
+++ b/gfx/src/nsThebesFontEnumerator.h
@@ -0,0 +1,24 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef _NSTHEBESFONTENUMERATOR_H_
+#define _NSTHEBESFONTENUMERATOR_H_
+
+#include "mozilla/Attributes.h"         // for final
+#include "nsIFontEnumerator.h"          // for NS_DECL_NSIFONTENUMERATOR, etc
+#include "nsISupports.h"                // for NS_DECL_ISUPPORTS
+
+class nsThebesFontEnumerator final : public nsIFontEnumerator
+{
+    ~nsThebesFontEnumerator() {}
+public:
+    nsThebesFontEnumerator();
+
+    NS_DECL_ISUPPORTS
+
+    NS_DECL_NSIFONTENUMERATOR
+};
+
+#endif /* _NSTHEBESFONTENUMERATOR_H_ */
diff --git a/gfx/src/nsThebesGfxFactory.cpp b/gfx/src/nsThebesGfxFactory.cpp
new file mode 100644
index 000000000..8e1e18d5c
--- /dev/null
+++ b/gfx/src/nsThebesGfxFactory.cpp
@@ -0,0 +1,63 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "gfxPlatform.h"                // for gfxPlatform
+#include "mozilla/Assertions.h"         // for MOZ_ASSERT_HELPER2
+#include "mozilla/Attributes.h"         // for final
+#include "mozilla/Module.h"             // for Module, Module::CIDEntry, etc
+#include "mozilla/ModuleUtils.h"
+#include "mozilla/mozalloc.h"           // for operator new
+#include "nsCOMPtr.h"                   // for nsCOMPtr
+#include "nsError.h"                    // for NS_ERROR_NO_AGGREGATION, etc
+#include "nsGfxCIID.h"                  // for NS_FONT_ENUMERATOR_CID, etc
+#include "nsID.h"                       // for NS_DEFINE_NAMED_CID, etc
+#include "nsIScriptableRegion.h"        // for nsIScriptableRegion
+#include "nsISupports.h"                // for NS_DECL_ISUPPORTS, etc
+#include "nsScriptableRegion.h"         // for nsScriptableRegion
+#include "nsThebesFontEnumerator.h"     // for nsThebesFontEnumerator
+
+NS_GENERIC_FACTORY_CONSTRUCTOR(nsThebesFontEnumerator)
+
+static nsresult
+nsScriptableRegionConstructor(nsISupports *aOuter, REFNSIID aIID, void **aResult)
+{
+  if (!aResult) {
+    return NS_ERROR_NULL_POINTER;
+  }
+  *aResult = nullptr;
+  if (aOuter) {
+    return NS_ERROR_NO_AGGREGATION;
+  }
+
+  nsCOMPtr<nsIScriptableRegion> scriptableRgn = new nsScriptableRegion();
+  return scriptableRgn->QueryInterface(aIID, aResult);
+}
+
+NS_DEFINE_NAMED_CID(NS_FONT_ENUMERATOR_CID);
+NS_DEFINE_NAMED_CID(NS_SCRIPTABLE_REGION_CID);
+
+static const mozilla::Module::CIDEntry kThebesCIDs[] = {
+    { &kNS_FONT_ENUMERATOR_CID, false, nullptr, nsThebesFontEnumeratorConstructor },
+    { &kNS_SCRIPTABLE_REGION_CID, false, nullptr, nsScriptableRegionConstructor },
+    { nullptr }
+};
+
+static const mozilla::Module::ContractIDEntry kThebesContracts[] = {
+    { "@mozilla.org/gfx/fontenumerator;1", &kNS_FONT_ENUMERATOR_CID },
+    { "@mozilla.org/gfx/region;1", &kNS_SCRIPTABLE_REGION_CID },
+    { nullptr }
+};
+
+static const mozilla::Module kThebesModule = {
+    mozilla::Module::kVersion,
+    kThebesCIDs,
+    kThebesContracts,
+    nullptr,
+    nullptr,
+    nullptr,
+    nullptr
+};
+
+NSMODULE_DEFN(nsGfxModule) = &kThebesModule;
diff --git a/gfx/src/nsThemeConstants.h b/gfx/src/nsThemeConstants.h
new file mode 100644
index 000000000..7825b9c6f
--- /dev/null
+++ b/gfx/src/nsThemeConstants.h
@@ -0,0 +1,296 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// No appearance at all.
+#define NS_THEME_NONE                                      0
+
+// A typical dialog button.
+#define NS_THEME_BUTTON                                    1
+
+// A radio element within a radio group.
+#define NS_THEME_RADIO                                     2
+
+// A checkbox element. 
+#define NS_THEME_CHECKBOX                                  3
+
+// A rectangular button that contains complex content
+// like images (e.g. HTML <button> elements)
+#define NS_THEME_BUTTON_BEVEL                              7
+
+// A themed focus outline (for outline:auto)
+#define NS_THEME_FOCUS_OUTLINE                             8
+
+// The toolbox that contains the toolbars.
+#define NS_THEME_TOOLBOX                                   11
+
+// A toolbar in an application window.
+#define NS_THEME_TOOLBAR                                   12
+
+// A single toolbar button (with no associated dropdown)
+#define NS_THEME_TOOLBARBUTTON                             13
+
+// A dual toolbar button (e.g., a Back button with a dropdown)
+#define NS_THEME_DUALBUTTON                                14
+
+// The dropdown portion of a toolbar button
+#define NS_THEME_TOOLBARBUTTON_DROPDOWN                    15
+
+// Various arrows that go in buttons
+#define NS_THEME_BUTTON_ARROW_UP                           16
+#define NS_THEME_BUTTON_ARROW_DOWN                         17
+#define NS_THEME_BUTTON_ARROW_NEXT                         18
+#define NS_THEME_BUTTON_ARROW_PREVIOUS                     19
+
+// A separator.  Can be horizontal or vertical.
+#define NS_THEME_SEPARATOR                                 20
+
+// The gripper for a toolbar.
+#define NS_THEME_TOOLBARGRIPPER                            21
+
+// A splitter.  Can be horizontal or vertical.
+#define NS_THEME_SPLITTER                                  22
+
+// A status bar in a main application window.
+#define NS_THEME_STATUSBAR                                 23
+
+// A single pane of a status bar.
+#define NS_THEME_STATUSBARPANEL                            24
+
+// The resizer background area in a status bar 
+// for the resizer widget in the corner of a window.
+#define NS_THEME_RESIZERPANEL                              25
+
+// The resizer itself.
+#define NS_THEME_RESIZER                                   26
+
+// List boxes
+#define NS_THEME_LISTBOX                                   31
+
+// A listbox item
+#define NS_THEME_LISTITEM                                  32
+
+// A tree widget
+#define NS_THEME_TREEVIEW                                  41
+
+// A tree item
+#define NS_THEME_TREEITEM                                  42
+
+// A tree widget twisty
+#define NS_THEME_TREETWISTY                                43
+
+// A tree widget branch line
+#define NS_THEME_TREELINE                                  44
+
+// A listbox or tree widget header
+#define NS_THEME_TREEHEADER                                45
+
+// An individual header cell
+#define NS_THEME_TREEHEADERCELL                            46
+
+// The sort arrow for a header.
+#define NS_THEME_TREEHEADERSORTARROW                       47
+
+// Open tree widget twisty
+#define NS_THEME_TREETWISTYOPEN                            48
+
+// A horizontal progress bar.
+#define NS_THEME_PROGRESSBAR                               51
+
+// The progress bar's progress indicator
+#define NS_THEME_PROGRESSCHUNK                             52
+
+// A vertical progress bar.
+#define NS_THEME_PROGRESSBAR_VERTICAL                      53
+
+// A vertical progress chunk
+#define NS_THEME_PROGRESSCHUNK_VERTICAL                    54
+
+// A horizontal meter bar.
+#define NS_THEME_METERBAR                                  55
+
+// The meter bar's meter indicator
+#define NS_THEME_METERCHUNK                                56
+
+// A single tab in a tab widget.
+#define NS_THEME_TAB                                       61
+
+// A single pane (inside the tabpanels container)
+#define NS_THEME_TABPANEL                                  62
+
+// The tab panels container.
+#define NS_THEME_TABPANELS                                 65
+
+// The tabs scroll arrows (left/right)
+#define NS_THEME_TAB_SCROLL_ARROW_BACK                     66
+#define NS_THEME_TAB_SCROLL_ARROW_FORWARD                  67
+
+// A tooltip
+#define NS_THEME_TOOLTIP                                   71
+
+// A spin control (up/down control for time/date pickers)
+#define NS_THEME_SPINNER                                   72
+
+// The up button of a spin control
+#define NS_THEME_SPINNER_UPBUTTON                          73
+
+// The down button of a spin control
+#define NS_THEME_SPINNER_DOWNBUTTON                        74
+
+// The textfield of a spin control
+#define NS_THEME_SPINNER_TEXTFIELD                         75
+
+// For HTML's <input type=number>
+#define NS_THEME_NUMBER_INPUT                              76
+
+// A scrollbar.
+#define NS_THEME_SCROLLBAR                                 80
+
+// A small scrollbar.
+#define NS_THEME_SCROLLBAR_SMALL                           81
+
+// The scrollbar slider
+#define NS_THEME_SCROLLBAR_HORIZONTAL                      82
+#define NS_THEME_SCROLLBAR_VERTICAL                        83
+
+// A scrollbar button (up/down/left/right)
+#define NS_THEME_SCROLLBARBUTTON_UP                        84
+#define NS_THEME_SCROLLBARBUTTON_DOWN                      85
+#define NS_THEME_SCROLLBARBUTTON_LEFT                      86
+#define NS_THEME_SCROLLBARBUTTON_RIGHT                     87
+
+// The scrollbar track
+#define NS_THEME_SCROLLBARTRACK_HORIZONTAL                 88
+#define NS_THEME_SCROLLBARTRACK_VERTICAL                   89
+
+// The scrollbar thumb
+#define NS_THEME_SCROLLBARTHUMB_HORIZONTAL                 90
+#define NS_THEME_SCROLLBARTHUMB_VERTICAL                   91
+
+// A non-disappearing scrollbar.
+#define NS_THEME_SCROLLBAR_NON_DISAPPEARING                92
+
+// A textfield or text area
+#define NS_THEME_TEXTFIELD                                 95
+
+// The caret of a text area
+#define NS_THEME_CARET                                     96
+
+// A multiline text field
+#define NS_THEME_TEXTFIELD_MULTILINE                       97
+
+// A searchfield
+#define NS_THEME_SEARCHFIELD                               98
+
+// A dropdown list.
+#define NS_THEME_MENULIST                                  101
+
+// The dropdown button(s) that open up a dropdown list.
+#define NS_THEME_MENULIST_BUTTON                           102
+
+// The text part of a dropdown list, to left of button
+#define NS_THEME_MENULIST_TEXT                             103
+
+// An editable textfield with a dropdown list (a combobox)
+#define NS_THEME_MENULIST_TEXTFIELD                        104
+
+// A slider
+#define NS_THEME_SCALE_HORIZONTAL                          111
+#define NS_THEME_SCALE_VERTICAL                            112
+
+// A slider's thumb
+#define NS_THEME_SCALETHUMB_HORIZONTAL                     113
+#define NS_THEME_SCALETHUMB_VERTICAL                       114
+
+// If the platform supports it, the left/right chunks
+// of the slider thumb
+#define NS_THEME_SCALETHUMBSTART                           115
+#define NS_THEME_SCALETHUMBEND                             116
+
+// The ticks for a slider.
+#define NS_THEME_SCALETHUMBTICK                            117
+
+// nsRangeFrame and its subparts
+#define NS_THEME_RANGE                                     120
+#define NS_THEME_RANGE_THUMB                               121
+
+// A groupbox
+#define NS_THEME_GROUPBOX                                  149
+
+// A generic container that always repaints on state
+// changes.  This is a hack to make checkboxes and
+// radio buttons work.
+#define NS_THEME_CHECKBOX_CONTAINER                        150
+#define NS_THEME_RADIO_CONTAINER                           151
+
+// The label part of a checkbox or radio button, used for painting
+// a focus outline.
+#define NS_THEME_CHECKBOX_LABEL                            152
+#define NS_THEME_RADIO_LABEL                               153
+
+// The focus outline box inside of a button
+#define NS_THEME_BUTTON_FOCUS                              154
+
+// Window and dialog backgrounds
+#define NS_THEME_WINDOW                                    200
+#define NS_THEME_DIALOG                                    201
+
+// Menu Bar background
+#define NS_THEME_MENUBAR                                   210
+// Menu Popup background
+#define NS_THEME_MENUPOPUP                                 211
+// <menu> and <menuitem> appearances
+#define NS_THEME_MENUITEM                                  212
+#define NS_THEME_CHECKMENUITEM                             213
+#define NS_THEME_RADIOMENUITEM                             214
+
+// menu checkbox/radio appearances
+#define NS_THEME_MENUCHECKBOX                              215
+#define NS_THEME_MENURADIO                                 216
+#define NS_THEME_MENUSEPARATOR                             217
+#define NS_THEME_MENUARROW                                 218
+// An image in the menu gutter, like in bookmarks or history
+#define NS_THEME_MENUIMAGE                                 219
+// For text on non-iconic menuitems only
+#define NS_THEME_MENUITEMTEXT                              220
+
+// Vista Rebars
+#define NS_THEME_WIN_COMMUNICATIONS_TOOLBOX                221
+#define NS_THEME_WIN_MEDIA_TOOLBOX                         222
+#define NS_THEME_WIN_BROWSERTABBAR_TOOLBOX                 223
+
+// Titlebar elements on the Mac
+#define NS_THEME_MAC_FULLSCREEN_BUTTON                     226
+
+// Mac help button
+#define NS_THEME_MAC_HELP_BUTTON                           227
+
+// Vista glass
+#define NS_THEME_WIN_BORDERLESS_GLASS                      229
+#define NS_THEME_WIN_GLASS                                 230
+
+// Windows themed window frame elements
+#define NS_THEME_WINDOW_TITLEBAR                           231
+#define NS_THEME_WINDOW_TITLEBAR_MAXIMIZED                 232
+#define NS_THEME_WINDOW_FRAME_LEFT                         233
+#define NS_THEME_WINDOW_FRAME_RIGHT                        234
+#define NS_THEME_WINDOW_FRAME_BOTTOM                       235
+#define NS_THEME_WINDOW_BUTTON_CLOSE                       236
+#define NS_THEME_WINDOW_BUTTON_MINIMIZE                    237
+#define NS_THEME_WINDOW_BUTTON_MAXIMIZE                    238
+#define NS_THEME_WINDOW_BUTTON_RESTORE                     239
+#define NS_THEME_WINDOW_BUTTON_BOX                         240
+#define NS_THEME_WINDOW_BUTTON_BOX_MAXIMIZED               241
+
+// moz-apperance style used in setting proper glass margins
+#define NS_THEME_WIN_EXCLUDE_GLASS                         242
+
+#define NS_THEME_MAC_VIBRANCY_LIGHT                        243
+#define NS_THEME_MAC_VIBRANCY_DARK                         244
+#define NS_THEME_MAC_DISCLOSURE_BUTTON_OPEN                245
+#define NS_THEME_MAC_DISCLOSURE_BUTTON_CLOSED              246
+
+#define NS_THEME_GTK_INFO_BAR                              247
+#define NS_THEME_MAC_SOURCE_LIST                           248
+#define NS_THEME_MAC_SOURCE_LIST_SELECTION                 249
+#define NS_THEME_MAC_ACTIVE_SOURCE_LIST_SELECTION          250
diff --git a/gfx/src/nsTransform2D.cpp b/gfx/src/nsTransform2D.cpp
new file mode 100644
index 000000000..becea4392
--- /dev/null
+++ b/gfx/src/nsTransform2D.cpp
@@ -0,0 +1,23 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+
+#include "nsTransform2D.h"
+
+void nsTransform2D :: TransformCoord(nscoord *ptX, nscoord *ptY) const
+{
+  *ptX = NSToCoordRound(*ptX * m00 + m20);
+  *ptY = NSToCoordRound(*ptY * m11 + m21);
+}
+
+void nsTransform2D :: TransformCoord(nscoord *aX, nscoord *aY, nscoord *aWidth, nscoord *aHeight) const
+{
+  nscoord x2 = *aX + *aWidth;
+  nscoord y2 = *aY + *aHeight;
+  TransformCoord(aX, aY);
+  TransformCoord(&x2, &y2);
+  *aWidth = x2 - *aX;
+  *aHeight = y2 - *aY;
+}
diff --git a/gfx/src/nsTransform2D.h b/gfx/src/nsTransform2D.h
new file mode 100644
index 000000000..8999b2cf3
--- /dev/null
+++ b/gfx/src/nsTransform2D.h
@@ -0,0 +1,86 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsTransform2D_h___
+#define nsTransform2D_h___
+
+#include "nsCoord.h"
+
+class nsTransform2D
+{
+private:
+ /**
+  * This represents the following matrix (note that the order of row/column
+  * indices is opposite to usual notation)
+  *
+  *      / m00   0   m20  \
+  * M =  |  0   m11  m21  |
+  *      \  0    0    1   /
+  *
+  * Transformation of a coordinate (x, y) is obtained by setting
+  * v = (x, y, 1)^T and evaluating  M . v
+  **/
+
+  float     m00, m11, m20, m21;
+
+public:
+  nsTransform2D(void)                         { m20 = m21 = 0.0f; m00 = m11 = 1.0f; }
+
+  ~nsTransform2D(void)                        { }
+
+ /**
+  * set this transform to a translation
+  *
+  * @param      tx, x translation
+  * @param      ty, y translation
+  **/
+
+  void SetToTranslate(float tx, float ty)    { m00 = m11 = 1.0f; m20 = tx; m21 = ty; }
+  
+ /**
+  * get the translation portion of this transform
+  *
+  * @param      pt, Point to return translation values in
+  **/
+
+  void GetTranslationCoord(nscoord *ptX, nscoord *ptY) const { *ptX = NSToCoordRound(m20); *ptY = NSToCoordRound(m21); }
+
+ /**
+  * apply matrix to vector
+  *
+  * @param    pt Point to transform
+  **/
+
+  void TransformCoord(nscoord *ptX, nscoord *ptY) const;
+
+ /**
+  * apply matrix to rect
+  *
+  * @param    rect Rect to transform
+  **/
+
+  void TransformCoord(nscoord *aX, nscoord *aY, nscoord *aWidth, nscoord *aHeight) const;
+
+ /**
+  * add a scale to a Transform via x, y pair
+  *
+  * @param    ptX x value to add as x scale
+  * @param    ptY y value to add as y scale
+  **/
+
+  void AddScale(float ptX, float ptY) { m00 *= ptX; m11 *= ptY; }
+
+ /**
+  * Set the scale (overriding any previous calls to AddScale, but leaving
+  * any existing translation).
+  *
+  * @param    ptX x value to add as x scale
+  * @param    ptY y value to add as y scale
+  **/
+
+  void SetScale(float ptX, float ptY) { m00 = ptX; m11 = ptY; }
+};
+
+#endif
author	Matt A. Tobin <mattatobin@localhost.localdomain>	2018-02-02 04:16:08 -0500
committer	Matt A. Tobin <mattatobin@localhost.localdomain>	2018-02-02 04:16:08 -0500
commit	5f8de423f190bbb79a62f804151bc24824fa32d8 (patch)
tree	10027f336435511475e392454359edea8e25895d /gfx/src
parent	49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff)
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