Merge branch 'master' into Basilisk-releasev2018.11.04

53 files changed, 941 insertions, 374 deletions

diff --git a/dom/base/nsGlobalWindow.cpp b/dom/base/nsGlobalWindow.cpp
index 88cebe42b..86160c77c 100644
--- a/dom/base/nsGlobalWindow.cpp
+++ b/dom/base/nsGlobalWindow.cpp
@@ -2023,7 +2023,7 @@ nsGlobalWindow::ClearControllers()
 }
 
 void
-nsGlobalWindow::FreeInnerObjects()
+nsGlobalWindow::FreeInnerObjects(bool aForDocumentOpen)
 {
   NS_ASSERTION(IsInnerWindow(), "Don't free inner objects on an outer window");
 
@@ -2082,8 +2082,10 @@ nsGlobalWindow::FreeInnerObjects()
     mDocumentURI = mDoc->GetDocumentURI();
     mDocBaseURI = mDoc->GetDocBaseURI();
 
-    while (mDoc->EventHandlingSuppressed()) {
-      mDoc->UnsuppressEventHandlingAndFireEvents(nsIDocument::eEvents, false);
+    if (!aForDocumentOpen) {
+      while (mDoc->EventHandlingSuppressed()) {
+        mDoc->UnsuppressEventHandlingAndFireEvents(nsIDocument::eEvents, false);
+      }
     }
 
     // Note: we don't have to worry about eAnimationsOnly suppressions because
@@ -3000,6 +3002,8 @@ nsGlobalWindow::SetNewDocument(nsIDocument* aDocument,
   nsCOMPtr<WindowStateHolder> wsh = do_QueryInterface(aState);
   NS_ASSERTION(!aState || wsh, "What kind of weird state are you giving me here?");
 
+  bool handleDocumentOpen = false;
+  
   JS::Rooted<JSObject*> newInnerGlobal(cx);
   if (reUseInnerWindow) {
     // We're reusing the current inner window.
@@ -3091,6 +3095,7 @@ nsGlobalWindow::SetNewDocument(nsIDocument* aDocument,
 
     if (currentInner && currentInner->GetWrapperPreserveColor()) {
       if (oldDoc == aDocument) {
+        handleDocumentOpen = true;
         // Move the navigator from the old inner window to the new one since
         // this is a document.write. This is safe from a same-origin point of
         // view because document.write can only be used by the same origin.
@@ -3115,7 +3120,7 @@ nsGlobalWindow::SetNewDocument(nsIDocument* aDocument,
       // Don't free objects on our current inner window if it's going to be
       // held in the bfcache.
       if (!currentInner->IsFrozen()) {
-        currentInner->FreeInnerObjects();
+        currentInner->FreeInnerObjects(handleDocumentOpen);
       }
     }
 
diff --git a/dom/base/nsGlobalWindow.h b/dom/base/nsGlobalWindow.h
index 467bc6796..80bf33b80 100644
--- a/dom/base/nsGlobalWindow.h
+++ b/dom/base/nsGlobalWindow.h
@@ -1380,7 +1380,7 @@ protected:
     }
   }
 
-  void FreeInnerObjects();
+  void FreeInnerObjects(bool aForDocumentOpen = false);
   nsGlobalWindow *CallerInnerWindow();
 
   // Only to be called on an inner window.
diff --git a/dom/geolocation/nsGeolocation.cpp b/dom/geolocation/nsGeolocation.cpp
index 201d4d89a..244018ee8 100644
--- a/dom/geolocation/nsGeolocation.cpp
+++ b/dom/geolocation/nsGeolocation.cpp
@@ -395,18 +395,6 @@ nsGeolocationRequest::Allow(JS::HandleValue aChoices)
 {
   MOZ_ASSERT(aChoices.isUndefined());
 
-  if (mRequester) {
-    // Record whether a location callback is fulfilled while the owner window
-    // is not visible.
-    bool isVisible = false;
-    nsCOMPtr<nsPIDOMWindowInner> window = mLocator->GetParentObject();
-
-    if (window) {
-      nsCOMPtr<nsIDocument> doc = window->GetDoc();
-      isVisible = doc && !doc->Hidden();
-    }
-  }
-
   if (mLocator->ClearPendingRequest(this)) {
     return NS_OK;
   }
diff --git a/dom/indexedDB/ActorsParent.cpp b/dom/indexedDB/ActorsParent.cpp
index e6fe9e2a8..58c113058 100644
--- a/dom/indexedDB/ActorsParent.cpp
+++ b/dom/indexedDB/ActorsParent.cpp
@@ -23,6 +23,7 @@
 #include "mozilla/AppProcessChecker.h"
 #include "mozilla/AutoRestore.h"
 #include "mozilla/Casting.h"
+#include "mozilla/CheckedInt.h"
 #include "mozilla/EndianUtils.h"
 #include "mozilla/ErrorNames.h"
 #include "mozilla/LazyIdleThread.h"
@@ -249,8 +250,6 @@ const char kSQLiteJournalSuffix[] = ".sqlite-journal";
 const char kSQLiteSHMSuffix[] = ".sqlite-shm";
 const char kSQLiteWALSuffix[] = ".sqlite-wal";
 
-const char kPrefIndexedDBEnabled[] = "dom.indexedDB.enabled";
-
 const char kPrefFileHandleEnabled[] = "dom.fileHandle.enabled";
 
 #define IDB_PREFIX "indexedDB"
@@ -784,29 +783,25 @@ MakeCompressedIndexDataValues(
 
     MOZ_ASSERT(!keyBuffer.IsEmpty());
 
-    // Don't let |infoLength| overflow.
-    if (NS_WARN_IF(UINT32_MAX - keyBuffer.Length() <
-                   CompressedByteCountForIndexId(info.mIndexId) +
-                   CompressedByteCountForNumber(keyBufferLength) +
-                   CompressedByteCountForNumber(sortKeyBufferLength))) {
-      IDB_REPORT_INTERNAL_ERR();
-      return NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR;
-    }
-
-    const uint32_t infoLength =
-      CompressedByteCountForIndexId(info.mIndexId) +
+    const CheckedUint32 infoLength =
+      CheckedUint32(CompressedByteCountForIndexId(info.mIndexId)) +
       CompressedByteCountForNumber(keyBufferLength) +
       CompressedByteCountForNumber(sortKeyBufferLength) +
       keyBufferLength +
       sortKeyBufferLength;
+    // Don't let |infoLength| overflow.
+    if (NS_WARN_IF(!infoLength.isValid())) {
+      IDB_REPORT_INTERNAL_ERR();
+      return NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR;
+    }
 
     // Don't let |blobDataLength| overflow.
-    if (NS_WARN_IF(UINT32_MAX - infoLength < blobDataLength)) {
+    if (NS_WARN_IF(UINT32_MAX - infoLength.value() < blobDataLength)) {
       IDB_REPORT_INTERNAL_ERR();
       return NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR;
     }
 
-    blobDataLength += infoLength;
+    blobDataLength += infoLength.value();
   }
 
   UniqueFreePtr<uint8_t> blobData(
@@ -21172,16 +21167,6 @@ FactoryOp::CheckPermission(ContentParent* aContentParent,
       return NS_ERROR_DOM_INDEXEDDB_NOT_ALLOWED_ERR;
     }
 
-    if (NS_WARN_IF(!Preferences::GetBool(kPrefIndexedDBEnabled, false))) {
-      if (aContentParent) {
-        // The DOM in the other process should have kept us from receiving any
-        // indexedDB messages so assume that the child is misbehaving.
-        aContentParent->KillHard("IndexedDB CheckPermission 1");
-      }
-
-      return NS_ERROR_DOM_INDEXEDDB_NOT_ALLOWED_ERR;
-    }
-
     const ContentPrincipalInfo& contentPrincipalInfo =
       principalInfo.get_ContentPrincipalInfo();
     if (contentPrincipalInfo.attrs().mPrivateBrowsingId != 0) {
diff --git a/dom/indexedDB/IDBFactory.cpp b/dom/indexedDB/IDBFactory.cpp
index 663828978..825d2ac36 100644
--- a/dom/indexedDB/IDBFactory.cpp
+++ b/dom/indexedDB/IDBFactory.cpp
@@ -47,12 +47,6 @@ namespace dom {
 using namespace mozilla::dom::quota;
 using namespace mozilla::ipc;
 
-namespace {
-
-const char kPrefIndexedDBEnabled[] = "dom.indexedDB.enabled";
-
-} // namespace
-
 class IDBFactory::BackgroundCreateCallback final
   : public nsIIPCBackgroundChildCreateCallback
 {
@@ -130,12 +124,6 @@ IDBFactory::CreateForWindow(nsPIDOMWindowInner* aWindow,
   nsCOMPtr<nsIPrincipal> principal;
   nsresult rv = AllowedForWindowInternal(aWindow, getter_AddRefs(principal));
 
-  if (!(NS_SUCCEEDED(rv) && nsContentUtils::IsSystemPrincipal(principal)) &&
-      NS_WARN_IF(!Preferences::GetBool(kPrefIndexedDBEnabled, false))) {
-    *aFactory = nullptr;
-    return NS_ERROR_DOM_INDEXEDDB_NOT_ALLOWED_ERR;
-  }
-
   if (rv == NS_ERROR_DOM_NOT_SUPPORTED_ERR) {
     NS_WARNING("IndexedDB is not permitted in a third-party window.");
     *aFactory = nullptr;
@@ -246,12 +234,6 @@ IDBFactory::CreateForMainThreadJSInternal(
   MOZ_ASSERT(NS_IsMainThread());
   MOZ_ASSERT(aPrincipalInfo);
 
-  if (aPrincipalInfo->type() != PrincipalInfo::TSystemPrincipalInfo &&
-      NS_WARN_IF(!Preferences::GetBool(kPrefIndexedDBEnabled, false))) {
-    *aFactory = nullptr;
-    return NS_ERROR_DOM_INDEXEDDB_NOT_ALLOWED_ERR;
-  }
-
   IndexedDatabaseManager* mgr = IndexedDatabaseManager::GetOrCreate();
   if (NS_WARN_IF(!mgr)) {
     IDB_REPORT_INTERNAL_ERR();
diff --git a/dom/indexedDB/KeyPath.cpp b/dom/indexedDB/KeyPath.cpp
index dc8d10668..30edd8cd7 100644
--- a/dom/indexedDB/KeyPath.cpp
+++ b/dom/indexedDB/KeyPath.cpp
@@ -14,6 +14,7 @@
 #include "xpcpublic.h"
 
 #include "mozilla/dom/BindingDeclarations.h"
+#include "mozilla/dom/BlobBinding.h"
 #include "mozilla/dom/IDBObjectStoreBinding.h"
 
 namespace mozilla {
@@ -100,7 +101,6 @@ GetJSValFromKeyPathString(JSContext* aCx,
     const char16_t* keyPathChars = token.BeginReading();
     const size_t keyPathLen = token.Length();
 
-    bool hasProp;
     if (!targetObject) {
       // We're still walking the chain of existing objects
       // http://w3c.github.io/IndexedDB/#dfn-evaluate-a-key-path-on-a-value
@@ -116,16 +116,77 @@ GetJSValFromKeyPathString(JSContext* aCx,
       }
       obj = &currentVal.toObject();
 
-      bool ok = JS_HasUCProperty(aCx, obj, keyPathChars, keyPathLen,
-                                 &hasProp);
+      // We call JS_GetOwnUCPropertyDescriptor on purpose (as opposed to
+      // JS_GetUCPropertyDescriptor) to avoid searching the prototype chain.
+      JS::Rooted<JS::PropertyDescriptor> desc(aCx);
+      bool ok = JS_GetOwnUCPropertyDescriptor(aCx, obj, keyPathChars,
+                                              keyPathLen, &desc);
       IDB_ENSURE_TRUE(ok, NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR);
 
-      if (hasProp) {
-        // Get if the property exists...
-        JS::Rooted<JS::Value> intermediate(aCx);
-        bool ok = JS_GetUCProperty(aCx, obj, keyPathChars, keyPathLen, &intermediate);
-        IDB_ENSURE_TRUE(ok, NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR);
+      JS::Rooted<JS::Value> intermediate(aCx);
+      bool hasProp = false;
+
+      if (desc.object()) {
+        intermediate = desc.value();
+        hasProp = true;
+      } else {
+        // If we get here it means the object doesn't have the property or the
+        // property is available throuch a getter. We don't want to call any
+        // getters to avoid potential re-entrancy.
+        // The blob object is special since its properties are available
+        // only through getters but we still want to support them for key
+        // extraction. So they need to be handled manually.
+        Blob* blob;
+        if (NS_SUCCEEDED(UNWRAP_OBJECT(Blob, &obj, blob))) {
+          if (token.EqualsLiteral("size")) {
+            ErrorResult rv;
+            uint64_t size = blob->GetSize(rv);
+            MOZ_ALWAYS_TRUE(!rv.Failed());
+
+            intermediate = JS_NumberValue(size);
+            hasProp = true;
+          } else if (token.EqualsLiteral("type")) {
+            nsString type;
+            blob->GetType(type);
+
+            JSString* string =
+              JS_NewUCStringCopyN(aCx, type.get(), type.Length());
+
+            intermediate = JS::StringValue(string);
+            hasProp = true;
+          } else {
+            RefPtr<File> file = blob->ToFile();
+            if (file) {
+              if (token.EqualsLiteral("name")) {
+                nsString name;
+                file->GetName(name);
+
+                JSString* string =
+                  JS_NewUCStringCopyN(aCx, name.get(), name.Length());
+
+                intermediate = JS::StringValue(string);
+                hasProp = true;
+              } else if (token.EqualsLiteral("lastModified")) {
+                ErrorResult rv;
+                int64_t lastModifiedDate = file->GetLastModified(rv);
+                MOZ_ALWAYS_TRUE(!rv.Failed());
+
+                intermediate = JS_NumberValue(lastModifiedDate);
+                hasProp = true;
+              } else if (token.EqualsLiteral("lastModifiedDate")) {
+                ErrorResult rv;
+                Date lastModifiedDate = file->GetLastModifiedDate(rv);
+                MOZ_ALWAYS_TRUE(!rv.Failed());
+
+                lastModifiedDate.ToDateObject(aCx, &intermediate);
+                hasProp = true;
+              }
+            }
+          }
+        }
+      }
 
+      if (hasProp) {
         // Treat explicitly undefined as an error.
         if (intermediate.isUndefined()) {
           return NS_ERROR_DOM_INDEXEDDB_DATA_ERR;
diff --git a/dom/media/AudioStream.cpp b/dom/media/AudioStream.cpp
index 896dee407..4b1d82c37 100644
--- a/dom/media/AudioStream.cpp
+++ b/dom/media/AudioStream.cpp
@@ -345,7 +345,6 @@ AudioStream::Init(uint32_t aNumChannels, uint32_t aRate,
   cubeb* cubebContext = CubebUtils::GetCubebContext();
   if (!cubebContext) {
     NS_WARNING("Can't get cubeb context!");
-    CubebUtils::ReportCubebStreamInitFailure(true);
     return NS_ERROR_DOM_MEDIA_CUBEB_INITIALIZATION_ERR;
   }
 
@@ -367,10 +366,8 @@ AudioStream::OpenCubeb(cubeb* aContext, cubeb_stream_params& aParams,
                         latency_frames,
                         DataCallback_S, StateCallback_S, this) == CUBEB_OK) {
     mCubebStream.reset(stream);
-    CubebUtils::ReportCubebBackendUsed();
   } else {
     NS_WARNING(nsPrintfCString("AudioStream::OpenCubeb() %p failed to init cubeb", this).get());
-    CubebUtils::ReportCubebStreamInitFailure(aIsFirst);
     return NS_ERROR_FAILURE;
   }
 
diff --git a/dom/media/CubebUtils.cpp b/dom/media/CubebUtils.cpp
index 93792e63b..0f0167d9c 100644
--- a/dom/media/CubebUtils.cpp
+++ b/dom/media/CubebUtils.cpp
@@ -239,31 +239,6 @@ cubeb* GetCubebContextUnlocked()
   return sCubebContext;
 }
 
-void ReportCubebBackendUsed()
-{
-  StaticMutexAutoLock lock(sMutex);
-
-  sAudioStreamInitEverSucceeded = true;
-
-  bool foundBackend = false;
-  for (uint32_t i = 0; i < ArrayLength(AUDIOSTREAM_BACKEND_ID_STR); i++) {
-    if (!strcmp(cubeb_get_backend_id(sCubebContext), AUDIOSTREAM_BACKEND_ID_STR[i])) {
-      foundBackend = true;
-    }
-  }
-}
-
-void ReportCubebStreamInitFailure(bool aIsFirst)
-{
-  StaticMutexAutoLock lock(sMutex);
-  if (!aIsFirst && !sAudioStreamInitEverSucceeded) {
-    // This machine has no audio hardware, or it's in really bad shape, don't
-    // send this info, since we want CUBEB_BACKEND_INIT_FAILURE_OTHER to detect
-    // failures to open multiple streams in a process over time.
-    return;
-  }
-}
-
 uint32_t GetCubebPlaybackLatencyInMilliseconds()
 {
   StaticMutexAutoLock lock(sMutex);
diff --git a/dom/media/CubebUtils.h b/dom/media/CubebUtils.h
index fa5fc2294..f43492374 100644
--- a/dom/media/CubebUtils.h
+++ b/dom/media/CubebUtils.h
@@ -35,8 +35,6 @@ double GetVolumeScale();
 bool GetFirstStream();
 cubeb* GetCubebContext();
 cubeb* GetCubebContextUnlocked();
-void ReportCubebStreamInitFailure(bool aIsFirstStream);
-void ReportCubebBackendUsed();
 uint32_t GetCubebPlaybackLatencyInMilliseconds();
 Maybe<uint32_t> GetCubebMSGLatencyInFrames();
 bool CubebLatencyPrefSet();
diff --git a/dom/media/GraphDriver.cpp b/dom/media/GraphDriver.cpp
index 47762c56e..b60dfee9d 100644
--- a/dom/media/GraphDriver.cpp
+++ b/dom/media/GraphDriver.cpp
@@ -623,9 +623,6 @@ AudioCallbackDriver::Init()
   cubeb* cubebContext = CubebUtils::GetCubebContext();
   if (!cubebContext) {
     NS_WARNING("Could not get cubeb context.");
-    if (!mFromFallback) {
-      CubebUtils::ReportCubebStreamInitFailure(true);
-    }
     return;
   }
 
@@ -710,18 +707,11 @@ AudioCallbackDriver::Init()
       NS_WARNING_ASSERTION(
         rv == CUBEB_OK,
         "Could not set the audio stream volume in GraphDriver.cpp");
-      CubebUtils::ReportCubebBackendUsed();
     } else {
 #ifdef MOZ_WEBRTC
       StaticMutexAutoUnlock unlock(AudioInputCubeb::Mutex());
 #endif
       NS_WARNING("Could not create a cubeb stream for MediaStreamGraph, falling back to a SystemClockDriver");
-      // Only report failures when we're not coming from a driver that was
-      // created itself as a fallback driver because of a previous audio driver
-      // failure.
-      if (!mFromFallback) {
-        CubebUtils::ReportCubebStreamInitFailure(firstStream);
-      }
       // Fall back to a driver using a normal thread. If needed,
       // the graph will try to re-open an audio stream later.
       MonitorAutoLock lock(GraphImpl()->GetMonitor());
diff --git a/dom/media/MediaData.h b/dom/media/MediaData.h
index a79aac6ed..905b4c1d9 100644
--- a/dom/media/MediaData.h
+++ b/dom/media/MediaData.h
@@ -14,6 +14,7 @@
 #include "nsIMemoryReporter.h"
 #include "SharedBuffer.h"
 #include "mozilla/RefPtr.h"
+#include "mozilla/Span.h"
 #include "mozilla/UniquePtr.h"
 #include "mozilla/UniquePtrExtensions.h"
 #include "nsTArray.h"
@@ -631,6 +632,8 @@ public:
   {
     return sizeof(*this) + mBuffer.ComputedSizeOfExcludingThis();
   }
+  // Access the buffer as a Span.
+  operator Span<const uint8_t>() { return MakeSpan(Data(), Size()); }
 
   const CryptoSample& mCrypto;
   RefPtr<MediaByteBuffer> mExtraData;
diff --git a/dom/media/MediaPrefs.h b/dom/media/MediaPrefs.h
index b237ecd3d..e67796edd 100644
--- a/dom/media/MediaPrefs.h
+++ b/dom/media/MediaPrefs.h
@@ -120,6 +120,9 @@ private:
 #ifdef MOZ_FFVPX
   DECL_MEDIA_PREF("media.ffvpx.enabled",                      PDMFFVPXEnabled, bool, true);
 #endif
+#ifdef MOZ_AV1
+  DECL_MEDIA_PREF("media.av1.enabled",                        AV1Enabled, bool, false);
+#endif
 #ifdef XP_WIN
   DECL_MEDIA_PREF("media.wmf.enabled",                        PDMWMFEnabled, bool, true);
   DECL_MEDIA_PREF("media.wmf.skip-blacklist",                 PDMWMFSkipBlacklist, bool, false);
diff --git a/dom/media/VideoUtils.cpp b/dom/media/VideoUtils.cpp
index b1a202c03..c06ba9070 100644
--- a/dom/media/VideoUtils.cpp
+++ b/dom/media/VideoUtils.cpp
@@ -207,8 +207,20 @@ already_AddRefed<SharedThreadPool> GetMediaThreadPool(MediaThreadType aType)
       name = "MediaPlayback";
       break;
   }
-  return SharedThreadPool::
+  RefPtr<SharedThreadPool> pool = SharedThreadPool::
     Get(nsDependentCString(name), MediaPrefs::MediaThreadPoolDefaultCount());
+
+  // Ensure a larger stack for platform decoder threads
+  if (aType == MediaThreadType::PLATFORM_DECODER) {
+    const uint32_t minStackSize = 512*1024;
+    uint32_t stackSize;
+    MOZ_ALWAYS_SUCCEEDS(pool->GetThreadStackSize(&stackSize));
+    if (stackSize < minStackSize) {
+      MOZ_ALWAYS_SUCCEEDS(pool->SetThreadStackSize(minStackSize));
+    }
+  }
+
+  return pool.forget();
 }
 
 bool
@@ -426,6 +438,16 @@ ParseMIMETypeString(const nsAString& aMIMEType,
   return ParseCodecsString(codecsStr, aOutCodecs);
 }
 
+template <int N>
+static bool
+StartsWith(const nsACString& string, const char (&prefix)[N])
+{
+    if (N - 1 > string.Length()) {
+      return false;
+    }
+    return memcmp(string.Data(), prefix, N - 1) == 0;
+}
+
 bool
 IsH264CodecString(const nsAString& aCodec)
 {
@@ -458,15 +480,14 @@ IsVP9CodecString(const nsAString& aCodec)
          aCodec.EqualsLiteral("vp9.0");
 }
 
-template <int N>
-static bool
-StartsWith(const nsACString& string, const char (&prefix)[N])
+#ifdef MOZ_AV1
+bool
+IsAV1CodecString(const nsAString& aCodec)
 {
-    if (N - 1 > string.Length()) {
-      return false;
-    }
-    return memcmp(string.Data(), prefix, N - 1) == 0;
+  return aCodec.EqualsLiteral("av1") ||
+    StartsWith(NS_ConvertUTF16toUTF8(aCodec), "av01");
 }
+#endif
 
 UniquePtr<TrackInfo>
 CreateTrackInfoWithMIMEType(const nsACString& aCodecMIMEType)
diff --git a/dom/media/VideoUtils.h b/dom/media/VideoUtils.h
index 441b63792..aaf0e9903 100644
--- a/dom/media/VideoUtils.h
+++ b/dom/media/VideoUtils.h
@@ -345,6 +345,11 @@ IsVP8CodecString(const nsAString& aCodec);
 bool
 IsVP9CodecString(const nsAString& aCodec);
 
+#ifdef MOZ_AV1
+bool
+IsAV1CodecString(const nsAString& aCodec);
+#endif
+
 // Try and create a TrackInfo with a given codec MIME type.
 UniquePtr<TrackInfo>
 CreateTrackInfoWithMIMEType(const nsACString& aCodecMIMEType);
diff --git a/dom/media/platforms/agnostic/AOMDecoder.cpp b/dom/media/platforms/agnostic/AOMDecoder.cpp
new file mode 100644
index 000000000..b5d21375e
--- /dev/null
+++ b/dom/media/platforms/agnostic/AOMDecoder.cpp
@@ -0,0 +1,332 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* 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 "AOMDecoder.h"
+#include "MediaResult.h"
+#include "TimeUnits.h"
+#include "aom/aomdx.h"
+#include "aom/aom_image.h"
+#include "gfx2DGlue.h"
+#include "mozilla/PodOperations.h"
+#include "mozilla/SyncRunnable.h"
+#include "nsError.h"
+#include "prsystem.h"
+
+#include <algorithm>
+
+#undef LOG
+#define LOG(arg, ...) MOZ_LOG(sPDMLog, mozilla::LogLevel::Debug, ("AOMDecoder(%p)::%s: " arg, this, __func__, ##__VA_ARGS__))
+
+namespace mozilla {
+
+using namespace gfx;
+using namespace layers;
+
+AOMDecoder::AOMDecoder(const CreateDecoderParams& aParams)
+  : mImageContainer(aParams.mImageContainer)
+  , mTaskQueue(aParams.mTaskQueue)
+  , mCallback(aParams.mCallback)
+  , mIsFlushing(false)
+  , mInfo(aParams.VideoConfig())
+{
+  PodZero(&mCodec);
+}
+
+AOMDecoder::~AOMDecoder()
+{
+}
+
+void
+AOMDecoder::Shutdown()
+{
+  aom_codec_destroy(&mCodec);
+}
+
+RefPtr<MediaDataDecoder::InitPromise>
+AOMDecoder::Init()
+{
+  int decode_threads = 2;
+
+  aom_codec_iface_t* dx = aom_codec_av1_dx();
+  if (mInfo.mDisplay.width >= 2048) {
+    decode_threads = 8;
+  }
+  else if (mInfo.mDisplay.width >= 1024) {
+    decode_threads = 4;
+  }
+  decode_threads = std::min(decode_threads, PR_GetNumberOfProcessors());
+
+  aom_codec_dec_cfg_t config;
+  PodZero(&config);
+  config.threads = decode_threads;
+  config.w = config.h = 0; // set after decode
+  config.allow_lowbitdepth = true;
+
+  aom_codec_flags_t flags = 0;
+  
+  if (!dx || aom_codec_dec_init(&mCodec, dx, &config, flags)) {
+    return InitPromise::CreateAndReject(NS_ERROR_DOM_MEDIA_FATAL_ERR, __func__);
+  }
+  return InitPromise::CreateAndResolve(TrackInfo::kVideoTrack, __func__);
+}
+
+void
+AOMDecoder::Flush()
+{
+  MOZ_ASSERT(mCallback->OnReaderTaskQueue());
+  mIsFlushing = true;
+  nsCOMPtr<nsIRunnable> r = NS_NewRunnableFunction([this] () {
+    // nothing to do for now.
+  });
+  SyncRunnable::DispatchToThread(mTaskQueue, r);
+  mIsFlushing = false;
+}
+
+// Ported from third_party/aom/tools_common.c.
+static aom_codec_err_t
+highbd_img_downshift(aom_image_t *dst, aom_image_t *src, int down_shift) {
+  int plane;
+  if (dst->d_w != src->d_w || dst->d_h != src->d_h)
+    return AOM_CODEC_INVALID_PARAM;
+  if (dst->x_chroma_shift != src->x_chroma_shift)
+    return AOM_CODEC_INVALID_PARAM;
+  if (dst->y_chroma_shift != src->y_chroma_shift)
+    return AOM_CODEC_INVALID_PARAM;
+  if (dst->fmt != (src->fmt & ~AOM_IMG_FMT_HIGHBITDEPTH))
+    return AOM_CODEC_INVALID_PARAM;
+  if (down_shift < 0)
+      return AOM_CODEC_INVALID_PARAM;
+  switch (dst->fmt) {
+    case AOM_IMG_FMT_I420:
+    case AOM_IMG_FMT_I422:
+    case AOM_IMG_FMT_I444:
+      break;
+    default:
+      return AOM_CODEC_INVALID_PARAM;
+  }
+  switch (src->fmt) {
+    case AOM_IMG_FMT_I42016:
+    case AOM_IMG_FMT_I42216:
+    case AOM_IMG_FMT_I44416:
+      break;
+    default:
+      // We don't support anything that's not 16 bit
+      return AOM_CODEC_UNSUP_BITSTREAM;
+  }
+  for (plane = 0; plane < 3; plane++) {
+    int w = src->d_w;
+    int h = src->d_h;
+    int x, y;
+    if (plane) {
+      w = (w + src->x_chroma_shift) >> src->x_chroma_shift;
+      h = (h + src->y_chroma_shift) >> src->y_chroma_shift;
+    }
+    for (y = 0; y < h; y++) {
+      uint16_t *p_src =
+          (uint16_t *)(src->planes[plane] + y * src->stride[plane]);
+      uint8_t *p_dst =
+          dst->planes[plane] + y * dst->stride[plane];
+      for (x = 0; x < w; x++) *p_dst++ = (*p_src++ >> down_shift) & 0xFF;
+    }
+  }
+  return AOM_CODEC_OK;
+}
+
+// UniquePtr dtor wrapper for aom_image_t.
+struct AomImageFree {
+  void operator()(aom_image_t* img) { aom_img_free(img); }
+};
+
+MediaResult
+AOMDecoder::DoDecode(MediaRawData* aSample)
+{
+  MOZ_ASSERT(mTaskQueue->IsCurrentThreadIn());
+
+#if defined(DEBUG)
+  NS_ASSERTION(IsKeyframe(*aSample) == aSample->mKeyframe,
+               "AOM Decode Keyframe error sample->mKeyframe and si.si_kf out of sync");
+#endif
+
+  if (aom_codec_err_t r = aom_codec_decode(&mCodec, aSample->Data(), aSample->Size(), nullptr)) {
+    LOG("AOM Decode error: %s", aom_codec_err_to_string(r));
+    return MediaResult(
+      NS_ERROR_DOM_MEDIA_DECODE_ERR,
+      RESULT_DETAIL("AOM error decoding AV1 sample: %s", aom_codec_err_to_string(r)));
+  }
+
+  aom_codec_iter_t iter = nullptr;
+  aom_image_t *img;
+  UniquePtr<aom_image_t, AomImageFree> img8;
+
+  while ((img = aom_codec_get_frame(&mCodec, &iter))) {
+    // Track whether the underlying buffer is 8 or 16 bits per channel.
+    bool highbd = bool(img->fmt & AOM_IMG_FMT_HIGHBITDEPTH);
+    if (highbd) {
+      // Downsample images with more than 8 bits per channel.
+      aom_img_fmt_t fmt8 = static_cast<aom_img_fmt_t>(img->fmt ^ AOM_IMG_FMT_HIGHBITDEPTH);
+      img8.reset(aom_img_alloc(NULL, fmt8, img->d_w, img->d_h, 16));
+      if (img8 == nullptr) {
+        LOG("Couldn't allocate bitdepth reduction target!");
+        return MediaResult(
+          NS_ERROR_OUT_OF_MEMORY,
+          RESULT_DETAIL("Couldn't allocate conversion buffer for AV1 frame"));
+      }
+      if (aom_codec_err_t r = highbd_img_downshift(img8.get(), img, img->bit_depth - 8)) {
+        return MediaResult(
+          NS_ERROR_DOM_MEDIA_DECODE_ERR,
+          RESULT_DETAIL("Error converting AV1 frame to 8 bits: %s",
+                        aom_codec_err_to_string(r)));
+      }
+      // img normally points to storage owned by mCodec, so it is not freed.
+      // To copy out the contents of img8 we can overwrite img with an alias.
+      // Since img is assigned at the start of the while loop and img8 is held
+      // outside that loop, the alias won't outlive the storage it points to.
+      img = img8.get();
+      highbd = false;
+    }
+
+    NS_ASSERTION(img->fmt == AOM_IMG_FMT_I420 ||
+                 img->fmt == AOM_IMG_FMT_I42016 ||
+                 img->fmt == AOM_IMG_FMT_I444 ||
+                 img->fmt == AOM_IMG_FMT_I44416,
+                 "AV1 image format not I420 or I444");
+
+    // Chroma shifts are rounded down as per the decoding examples in the SDK
+    VideoData::YCbCrBuffer b;
+    b.mPlanes[0].mData = img->planes[0];
+    b.mPlanes[0].mStride = img->stride[0];
+    b.mPlanes[0].mHeight = img->d_h;
+    b.mPlanes[0].mWidth = img->d_w;
+    b.mPlanes[0].mOffset = 0;
+    b.mPlanes[0].mSkip = highbd ? 1 : 0;
+
+    b.mPlanes[1].mData = img->planes[1];
+    b.mPlanes[1].mStride = img->stride[1];
+    b.mPlanes[1].mOffset = 0;
+    b.mPlanes[1].mSkip = highbd ? 1 : 0;
+
+    b.mPlanes[2].mData = img->planes[2];
+    b.mPlanes[2].mStride = img->stride[2];
+    b.mPlanes[2].mOffset = 0;
+    b.mPlanes[2].mSkip = highbd ? 1 : 0;
+
+    if (img->fmt == AOM_IMG_FMT_I420 ||
+        img->fmt == AOM_IMG_FMT_I42016) {
+      b.mPlanes[1].mHeight = (img->d_h + 1) >> img->y_chroma_shift;
+      b.mPlanes[1].mWidth = (img->d_w + 1) >> img->x_chroma_shift;
+
+      b.mPlanes[2].mHeight = (img->d_h + 1) >> img->y_chroma_shift;
+      b.mPlanes[2].mWidth = (img->d_w + 1) >> img->x_chroma_shift;
+    } else if (img->fmt == AOM_IMG_FMT_I444) {
+      b.mPlanes[1].mHeight = img->d_h;
+      b.mPlanes[1].mWidth = img->d_w;
+
+      b.mPlanes[2].mHeight = img->d_h;
+      b.mPlanes[2].mWidth = img->d_w;
+    } else {
+      LOG("AOM Unknown image format");
+      return MediaResult(NS_ERROR_DOM_MEDIA_DECODE_ERR,
+                         RESULT_DETAIL("AOM Unknown image format"));
+    }
+
+    RefPtr<VideoData> v =
+      VideoData::CreateAndCopyData(mInfo,
+                                   mImageContainer,
+                                   aSample->mOffset,
+                                   aSample->mTime,
+                                   aSample->mDuration,
+                                   b,
+                                   aSample->mKeyframe,
+                                   aSample->mTimecode,
+                                   mInfo.ScaledImageRect(img->d_w,
+                                                         img->d_h));
+
+    if (!v) {
+      LOG("Image allocation error source %ux%u display %ux%u picture %ux%u",
+          img->d_w, img->d_h, mInfo.mDisplay.width, mInfo.mDisplay.height,
+          mInfo.mImage.width, mInfo.mImage.height);
+      return MediaResult(NS_ERROR_OUT_OF_MEMORY, __func__);
+    }
+    mCallback->Output(v);
+  }
+  return NS_OK;
+}
+
+void
+AOMDecoder::ProcessDecode(MediaRawData* aSample)
+{
+  MOZ_ASSERT(mTaskQueue->IsCurrentThreadIn());
+  if (mIsFlushing) {
+    return;
+  }
+  MediaResult rv = DoDecode(aSample);
+  if (NS_FAILED(rv)) {
+    mCallback->Error(rv);
+  } else {
+    mCallback->InputExhausted();
+  }
+}
+
+void
+AOMDecoder::Input(MediaRawData* aSample)
+{
+  MOZ_ASSERT(mCallback->OnReaderTaskQueue());
+  mTaskQueue->Dispatch(NewRunnableMethod<RefPtr<MediaRawData>>(
+                       this, &AOMDecoder::ProcessDecode, aSample));
+}
+
+void
+AOMDecoder::ProcessDrain()
+{
+  MOZ_ASSERT(mTaskQueue->IsCurrentThreadIn());
+  mCallback->DrainComplete();
+}
+
+void
+AOMDecoder::Drain()
+{
+  MOZ_ASSERT(mCallback->OnReaderTaskQueue());
+  mTaskQueue->Dispatch(NewRunnableMethod(this, &AOMDecoder::ProcessDrain));
+}
+
+/* static */
+bool
+AOMDecoder::IsAV1(const nsACString& aMimeType)
+{
+  return aMimeType.EqualsLiteral("video/webm; codecs=av1") ||
+         aMimeType.EqualsLiteral("video/av1");
+}
+
+/* static */
+bool
+AOMDecoder::IsKeyframe(Span<const uint8_t> aBuffer) {
+  aom_codec_stream_info_t info;
+  PodZero(&info);
+
+  aom_codec_peek_stream_info(aom_codec_av1_dx(),
+                             aBuffer.Elements(),
+                             aBuffer.Length(),
+                             &info);
+
+  return bool(info.is_kf);
+}
+
+/* static */
+nsIntSize
+AOMDecoder::GetFrameSize(Span<const uint8_t> aBuffer) {
+  aom_codec_stream_info_t info;
+  PodZero(&info);
+
+  aom_codec_peek_stream_info(aom_codec_av1_dx(),
+                             aBuffer.Elements(),
+                             aBuffer.Length(),
+                             &info);
+
+  return nsIntSize(info.w, info.h);
+}
+
+} // namespace mozilla
+#undef LOG
diff --git a/dom/media/platforms/agnostic/AOMDecoder.h b/dom/media/platforms/agnostic/AOMDecoder.h
new file mode 100644
index 000000000..ec6b1f95a
--- /dev/null
+++ b/dom/media/platforms/agnostic/AOMDecoder.h
@@ -0,0 +1,62 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* 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/. */
+
+#if !defined(AOMDecoder_h_)
+#define AOMDecoder_h_
+
+#include "PlatformDecoderModule.h"
+#include "mozilla/Span.h"
+
+#include <stdint.h>
+#include "aom/aom_decoder.h"
+
+namespace mozilla {
+
+class AOMDecoder : public MediaDataDecoder
+{
+public:
+  explicit AOMDecoder(const CreateDecoderParams& aParams);
+
+  RefPtr<InitPromise> Init() override;
+  void Input(MediaRawData* aSample) override;
+  void Flush() override;
+  void Drain() override;
+  void Shutdown() override;
+  const char* GetDescriptionName() const override
+  {
+    return "libaom (AV1) video decoder";
+  }
+
+  // Return true if aMimeType is a one of the strings used
+  // by our demuxers to identify AV1 streams.
+  static bool IsAV1(const nsACString& aMimeType);
+
+  // Return true if a sample is a keyframe.
+  static bool IsKeyframe(Span<const uint8_t> aBuffer);
+
+  // Return the frame dimensions for a sample.
+  static nsIntSize GetFrameSize(Span<const uint8_t> aBuffer);
+
+private:
+  ~AOMDecoder();
+  void ProcessDecode(MediaRawData* aSample);
+  MediaResult DoDecode(MediaRawData* aSample);
+  void ProcessDrain();
+
+  const RefPtr<layers::ImageContainer> mImageContainer;
+  const RefPtr<TaskQueue> mTaskQueue;
+  MediaDataDecoderCallback* mCallback;
+  Atomic<bool> mIsFlushing;
+
+  // AOM decoder state
+  aom_codec_ctx_t mCodec;
+
+  const VideoInfo& mInfo;
+};
+
+} // namespace mozilla
+
+#endif // AOMDecoder_h_
diff --git a/dom/media/platforms/agnostic/AgnosticDecoderModule.cpp b/dom/media/platforms/agnostic/AgnosticDecoderModule.cpp
index 7bd75b7fe..cf5ed3d22 100644
--- a/dom/media/platforms/agnostic/AgnosticDecoderModule.cpp
+++ b/dom/media/platforms/agnostic/AgnosticDecoderModule.cpp
@@ -5,6 +5,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "AgnosticDecoderModule.h"
+#include "MediaPrefs.h"
 #include "mozilla/Logging.h"
 #include "OpusDecoder.h"
 #include "VorbisDecoder.h"
@@ -12,6 +13,10 @@
 #include "WAVDecoder.h"
 #include "TheoraDecoder.h"
 
+#ifdef MOZ_AV1
+#include "AOMDecoder.h"
+#endif
+
 namespace mozilla {
 
 bool
@@ -24,6 +29,11 @@ AgnosticDecoderModule::SupportsMimeType(const nsACString& aMimeType,
     VorbisDataDecoder::IsVorbis(aMimeType) ||
     WaveDataDecoder::IsWave(aMimeType) ||
     TheoraDecoder::IsTheora(aMimeType);
+#ifdef MOZ_AV1
+  if (MediaPrefs::AV1Enabled()) {
+    supports |= AOMDecoder::IsAV1(aMimeType);
+  }
+#endif
   MOZ_LOG(sPDMLog, LogLevel::Debug, ("Agnostic decoder %s requested type",
         supports ? "supports" : "rejects"));
   return supports;
@@ -36,7 +46,14 @@ AgnosticDecoderModule::CreateVideoDecoder(const CreateDecoderParams& aParams)
 
   if (VPXDecoder::IsVPX(aParams.mConfig.mMimeType)) {
     m = new VPXDecoder(aParams);
-  } else if (TheoraDecoder::IsTheora(aParams.mConfig.mMimeType)) {
+  }
+#ifdef MOZ_AV1
+  else if (AOMDecoder::IsAV1(aParams.mConfig.mMimeType) &&
+           MediaPrefs::AV1Enabled()) {
+    m = new AOMDecoder(aParams);
+  }
+#endif
+  else if (TheoraDecoder::IsTheora(aParams.mConfig.mMimeType)) {
     m = new TheoraDecoder(aParams);
   }
 
diff --git a/dom/media/platforms/agnostic/VPXDecoder.cpp b/dom/media/platforms/agnostic/VPXDecoder.cpp
index 77c81b51b..f2f84487f 100644
--- a/dom/media/platforms/agnostic/VPXDecoder.cpp
+++ b/dom/media/platforms/agnostic/VPXDecoder.cpp
@@ -22,7 +22,7 @@ namespace mozilla {
 using namespace gfx;
 using namespace layers;
 
-static int MimeTypeToCodec(const nsACString& aMimeType)
+static VPXDecoder::Codec MimeTypeToCodec(const nsACString& aMimeType)
 {
   if (aMimeType.EqualsLiteral("video/webm; codecs=vp8")) {
     return VPXDecoder::Codec::VP8;
@@ -31,7 +31,7 @@ static int MimeTypeToCodec(const nsACString& aMimeType)
   } else if (aMimeType.EqualsLiteral("video/vp9")) {
     return VPXDecoder::Codec::VP9;
   }
-  return -1;
+  return VPXDecoder::Codec::Unknown;
 }
 
 VPXDecoder::VPXDecoder(const CreateDecoderParams& aParams)
@@ -101,17 +101,10 @@ MediaResult
 VPXDecoder::DoDecode(MediaRawData* aSample)
 {
   MOZ_ASSERT(mTaskQueue->IsCurrentThreadIn());
+
 #if defined(DEBUG)
-  vpx_codec_stream_info_t si;
-  PodZero(&si);
-  si.sz = sizeof(si);
-  if (mCodec == Codec::VP8) {
-    vpx_codec_peek_stream_info(vpx_codec_vp8_dx(), aSample->Data(), aSample->Size(), &si);
-  } else if (mCodec == Codec::VP9) {
-    vpx_codec_peek_stream_info(vpx_codec_vp9_dx(), aSample->Data(), aSample->Size(), &si);
-  }
-  NS_ASSERTION(bool(si.is_kf) == aSample->mKeyframe,
-               "VPX Decode Keyframe error sample->mKeyframe and si.si_kf out of sync");
+  NS_ASSERTION(IsKeyframe(*aSample, mCodec) == aSample->mKeyframe,
+               "VPX Decode Keyframe error sample->mKeyframe and sample data out of sync");
 #endif
 
   if (vpx_codec_err_t r = vpx_codec_decode(&mVPX, aSample->Data(), aSample->Size(), nullptr, 0)) {
@@ -249,5 +242,41 @@ VPXDecoder::IsVP9(const nsACString& aMimeType)
   return IsVPX(aMimeType, VPXDecoder::VP9);
 }
 
+/* static */
+bool
+VPXDecoder::IsKeyframe(Span<const uint8_t> aBuffer, Codec aCodec)
+{
+  vpx_codec_stream_info_t si;
+  PodZero(&si);
+  si.sz = sizeof(si);
+
+  if (aCodec == Codec::VP8) {
+    vpx_codec_peek_stream_info(vpx_codec_vp8_dx(), aBuffer.Elements(), aBuffer.Length(), &si);
+    return bool(si.is_kf);
+  } else if (aCodec == Codec::VP9) {
+    vpx_codec_peek_stream_info(vpx_codec_vp9_dx(), aBuffer.Elements(), aBuffer.Length(), &si);
+    return bool(si.is_kf);
+  }
+
+  return false;
+}
+
+/* static */
+nsIntSize
+VPXDecoder::GetFrameSize(Span<const uint8_t> aBuffer, Codec aCodec)
+{
+  vpx_codec_stream_info_t si;
+  PodZero(&si);
+  si.sz = sizeof(si);
+
+  if (aCodec == Codec::VP8) {
+    vpx_codec_peek_stream_info(vpx_codec_vp8_dx(), aBuffer.Elements(), aBuffer.Length(), &si);
+  } else if (aCodec == Codec::VP9) {
+    vpx_codec_peek_stream_info(vpx_codec_vp9_dx(), aBuffer.Elements(), aBuffer.Length(), &si);
+  }
+
+  return nsIntSize(si.w, si.h);
+}
+
 } // namespace mozilla
 #undef LOG
diff --git a/dom/media/platforms/agnostic/VPXDecoder.h b/dom/media/platforms/agnostic/VPXDecoder.h
index d420ec069..4e8d83617 100644
--- a/dom/media/platforms/agnostic/VPXDecoder.h
+++ b/dom/media/platforms/agnostic/VPXDecoder.h
@@ -7,6 +7,7 @@
 #define VPXDecoder_h_
 
 #include "PlatformDecoderModule.h"
+#include "mozilla/Span.h"
 
 #include <stdint.h>
 #define VPX_DONT_DEFINE_STDINT_TYPES
@@ -36,7 +37,8 @@ public:
 
   enum Codec: uint8_t {
     VP8 = 1 << 0,
-    VP9 = 1 << 1
+    VP9 = 1 << 1,
+    Unknown = 1 << 7,
   };
 
   // Return true if aMimeType is a one of the strings used by our demuxers to
@@ -46,6 +48,12 @@ public:
   static bool IsVP8(const nsACString& aMimeType);
   static bool IsVP9(const nsACString& aMimeType);
 
+  // Return true if a sample is a keyframe for the specified codec.
+  static bool IsKeyframe(Span<const uint8_t> aBuffer, Codec aCodec);
+
+  // Return the frame dimensions for a sample for the specified codec.
+  static nsIntSize GetFrameSize(Span<const uint8_t> aBuffer, Codec aCodec);
+
 private:
   void ProcessDecode(MediaRawData* aSample);
   MediaResult DoDecode(MediaRawData* aSample);
@@ -61,7 +69,7 @@ private:
 
   const VideoInfo& mInfo;
 
-  const int mCodec;
+  const Codec mCodec;
 };
 
 } // namespace mozilla
diff --git a/dom/media/platforms/ffmpeg/FFmpegDataDecoder.cpp b/dom/media/platforms/ffmpeg/FFmpegDataDecoder.cpp
index 8cb5c8578..8655ce25f 100644
--- a/dom/media/platforms/ffmpeg/FFmpegDataDecoder.cpp
+++ b/dom/media/platforms/ffmpeg/FFmpegDataDecoder.cpp
@@ -69,12 +69,21 @@ FFmpegDataDecoder<LIBAV_VER>::InitDecoder()
     mCodecContext->extradata_size = mExtraData->Length();
     // FFmpeg may use SIMD instructions to access the data which reads the
     // data in 32 bytes block. Must ensure we have enough data to read.
+    uint32_t padding_size =
 #if LIBAVCODEC_VERSION_MAJOR >= 58
-    mExtraData->AppendElements(AV_INPUT_BUFFER_PADDING_SIZE);
+      AV_INPUT_BUFFER_PADDING_SIZE;
 #else
-    mExtraData->AppendElements(FF_INPUT_BUFFER_PADDING_SIZE);
+      FF_INPUT_BUFFER_PADDING_SIZE;
 #endif
-    mCodecContext->extradata = mExtraData->Elements();
+    mCodecContext->extradata = static_cast<uint8_t*>(
+      mLib->av_malloc(mExtraData->Length() + padding_size));
+    if (!mCodecContext->extradata) {
+      return MediaResult(NS_ERROR_OUT_OF_MEMORY,
+                        RESULT_DETAIL("Couldn't init ffmpeg extradata"));
+    }
+    memcpy(mCodecContext->extradata,
+           mExtraData->Elements(),
+           mExtraData->Length());
   } else {
     mCodecContext->extradata_size = 0;
   }
@@ -165,6 +174,9 @@ FFmpegDataDecoder<LIBAV_VER>::ProcessShutdown()
   StaticMutexAutoLock mon(sMonitor);
 
   if (mCodecContext) {
+    if (mCodecContext->extradata) {
+      mLib->av_freep(&mCodecContext->extradata);
+    }
     mLib->avcodec_close(mCodecContext);
     mLib->av_freep(&mCodecContext);
 #if LIBAVCODEC_VERSION_MAJOR >= 55
diff --git a/dom/media/platforms/ffmpeg/FFmpegLibWrapper.cpp b/dom/media/platforms/ffmpeg/FFmpegLibWrapper.cpp
index 6302882a6..e1c326818 100644
--- a/dom/media/platforms/ffmpeg/FFmpegLibWrapper.cpp
+++ b/dom/media/platforms/ffmpeg/FFmpegLibWrapper.cpp
@@ -7,6 +7,7 @@
 #include "MediaPrefs.h"
 #include "mozilla/PodOperations.h"
 #include "mozilla/Types.h"
+#include "PlatformDecoderModule.h"
 #include "prlink.h"
 
 #define AV_LOG_DEBUG    48
diff --git a/dom/media/platforms/ffmpeg/FFmpegLibWrapper.h b/dom/media/platforms/ffmpeg/FFmpegLibWrapper.h
index d6944a1d8..c6c43a4ae 100644
--- a/dom/media/platforms/ffmpeg/FFmpegLibWrapper.h
+++ b/dom/media/platforms/ffmpeg/FFmpegLibWrapper.h
@@ -5,6 +5,7 @@
 #ifndef __FFmpegLibWrapper_h__
 #define __FFmpegLibWrapper_h__
 
+#include "mozilla/Attributes.h"
 #include "mozilla/Types.h"
 
 struct AVCodec;
@@ -91,4 +92,4 @@ private:
 
 } // namespace mozilla
 
-#endif // FFmpegLibWrapper
\ No newline at end of file
+#endif // FFmpegLibWrapper
diff --git a/dom/media/platforms/ffmpeg/ffvpx/moz.build b/dom/media/platforms/ffmpeg/ffvpx/moz.build
index aee58b5b0..c0041a4d4 100644
--- a/dom/media/platforms/ffmpeg/ffvpx/moz.build
+++ b/dom/media/platforms/ffmpeg/ffvpx/moz.build
@@ -20,7 +20,7 @@ SOURCES += [
 ]
 LOCAL_INCLUDES += [
     '..',
-    '../ffmpeg57/include',
+    '../ffmpeg58/include',
 ]
 
 if CONFIG['OS_ARCH'] == 'WINNT':
diff --git a/dom/media/platforms/moz.build b/dom/media/platforms/moz.build
index 3fb0cc842..be13d31c4 100644
--- a/dom/media/platforms/moz.build
+++ b/dom/media/platforms/moz.build
@@ -55,6 +55,14 @@ if CONFIG['MOZ_FFMPEG']:
         'ffmpeg',
     ]
 
+if CONFIG['MOZ_AV1']:
+    EXPORTS += [
+        'agnostic/AOMDecoder.h',
+    ]
+    UNIFIED_SOURCES += [
+        'agnostic/AOMDecoder.cpp',
+    ]
+
 if CONFIG['MOZ_APPLEMEDIA']:
   EXPORTS += [
       'apple/AppleDecoderModule.h',
diff --git a/dom/media/test/bug580982.webm b/dom/media/test/bug1377278.webm
index 802019f39..802019f39 100644
--- a/dom/media/test/bug580982.webm
+++ b/dom/media/test/bug1377278.webm
diff --git a/dom/media/test/bug580982.webm^headers^ b/dom/media/test/bug1377278.webm^headers^
index 4030ea1d3..4030ea1d3 100644
--- a/dom/media/test/bug580982.webm^headers^
+++ b/dom/media/test/bug1377278.webm^headers^
diff --git a/dom/media/test/manifest.js b/dom/media/test/manifest.js
index c6d533c1b..7e30cc97d 100644
--- a/dom/media/test/manifest.js
+++ b/dom/media/test/manifest.js
@@ -224,6 +224,9 @@ var gPlayTests = [
   // Test playback of a webm file
   { name:"seek-short.webm", type:"video/webm", duration:0.23 },
 
+  // Test playback of a webm file with 'matroska' doctype
+  { name:"bug1377278.webm", type:"video/webm", duration:4.0 },
+
   // Test playback of a WebM file with non-zero start time.
   { name:"split.webm", type:"video/webm", duration:1.967 },
 
@@ -532,7 +535,6 @@ var gErrorTests = [
   { name:"448636.ogv", type:"video/ogg" },
   { name:"bug504843.ogv", type:"video/ogg" },
   { name:"bug501279.ogg", type:"audio/ogg" },
-  { name:"bug580982.webm", type:"video/webm" },
   { name:"bug603918.webm", type:"video/webm" },
   { name:"bug604067.webm", type:"video/webm" },
   { name:"bogus.duh", type:"bogus/duh" }
diff --git a/dom/media/test/mochitest.ini b/dom/media/test/mochitest.ini
index ddabf78b6..742ac1b1c 100644
--- a/dom/media/test/mochitest.ini
+++ b/dom/media/test/mochitest.ini
@@ -382,8 +382,6 @@ support-files =
   bug556821.ogv^headers^
   bug557094.ogv
   bug557094.ogv^headers^
-  bug580982.webm
-  bug580982.webm^headers^
   bug603918.webm
   bug603918.webm^headers^
   bug604067.webm
@@ -395,6 +393,8 @@ support-files =
   bug1301226.wav^headers^
   bug1301226-odd.wav
   bug1301226-odd.wav^headers^
+  bug1377278.webm
+  bug1377278.webm^headers^
   can_play_type_dash.js
   can_play_type_ogg.js
   can_play_type_wave.js
diff --git a/dom/media/webm/WebMDecoder.cpp b/dom/media/webm/WebMDecoder.cpp
index b41de6d40..9575d6e42 100644
--- a/dom/media/webm/WebMDecoder.cpp
+++ b/dom/media/webm/WebMDecoder.cpp
@@ -5,6 +5,10 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "mozilla/Preferences.h"
+#ifdef MOZ_AV1
+#include "AOMDecoder.h"
+#endif
+#include "MediaPrefs.h"
 #include "MediaDecoderStateMachine.h"
 #include "WebMDemuxer.h"
 #include "WebMDecoder.h"
@@ -65,6 +69,11 @@ WebMDecoder::CanHandleMediaType(const nsACString& aMIMETypeExcludingCodecs,
 
       continue;
     }
+#ifdef MOZ_AV1
+    if (MediaPrefs::AV1Enabled() && IsAV1CodecString(codec)) {
+      continue;
+    }
+#endif
     // Some unsupported codec.
     return false;
   }
diff --git a/dom/media/webm/WebMDemuxer.cpp b/dom/media/webm/WebMDemuxer.cpp
index 20ed71581..013da9b2c 100644
--- a/dom/media/webm/WebMDemuxer.cpp
+++ b/dom/media/webm/WebMDemuxer.cpp
@@ -8,7 +8,11 @@
 #include "MediaDecoderStateMachine.h"
 #include "AbstractMediaDecoder.h"
 #include "MediaResource.h"
+#ifdef MOZ_AV1
+#include "AOMDecoder.h"
+#endif
 #include "OpusDecoder.h"
+#include "VPXDecoder.h"
 #include "WebMDemuxer.h"
 #include "WebMBufferedParser.h"
 #include "gfx2DGlue.h"
@@ -24,12 +28,9 @@
 #include "mozilla/Sprintf.h"
 
 #include <algorithm>
+#include <numeric>
 #include <stdint.h>
 
-#define VPX_DONT_DEFINE_STDINT_TYPES
-#include "vpx/vp8dx.h"
-#include "vpx/vpx_decoder.h"
-
 #define WEBM_DEBUG(arg, ...) MOZ_LOG(gMediaDemuxerLog, mozilla::LogLevel::Debug, ("WebMDemuxer(%p)::%s: " arg, this, __func__, ##__VA_ARGS__))
 extern mozilla::LazyLogModule gMediaDemuxerLog;
 
@@ -322,6 +323,9 @@ WebMDemuxer::ReadMetadata()
         case NESTEGG_CODEC_VP9:
           mInfo.mVideo.mMimeType = "video/webm; codecs=vp9";
           break;
+        case NESTEGG_CODEC_AV1:
+          mInfo.mVideo.mMimeType = "video/webm; codecs=av1";
+          break;
         default:
           NS_WARNING("Unknown WebM video codec");
           return NS_ERROR_FAILURE;
@@ -549,7 +553,7 @@ WebMDemuxer::GetTrackCrypto(TrackInfo::TrackType aType, size_t aTrackNumber) {
   return crypto;
 }
 
-bool
+nsresult
 WebMDemuxer::GetNextPacket(TrackInfo::TrackType aType, MediaRawDataQueue *aSamples)
 {
   if (mIsMediaSource) {
@@ -557,17 +561,18 @@ WebMDemuxer::GetNextPacket(TrackInfo::TrackType aType, MediaRawDataQueue *aSampl
     EnsureUpToDateIndex();
   }
 
-  RefPtr<NesteggPacketHolder> holder(NextPacket(aType));
+  RefPtr<NesteggPacketHolder> holder;
+  nsresult rv = NextPacket(aType, holder);
 
-  if (!holder) {
-    return false;
+  if (NS_FAILED(rv)) {
+    return rv;
   }
 
   int r = 0;
   unsigned int count = 0;
   r = nestegg_packet_count(holder->Packet(), &count);
   if (r == -1) {
-    return false;
+    return NS_ERROR_DOM_MEDIA_DEMUXER_ERR;
   }
   int64_t tstamp = holder->Timestamp();
   int64_t duration = holder->Duration();
@@ -578,7 +583,11 @@ WebMDemuxer::GetNextPacket(TrackInfo::TrackType aType, MediaRawDataQueue *aSampl
   // video frame.
   int64_t next_tstamp = INT64_MIN;
   if (aType == TrackInfo::kAudioTrack) {
-    RefPtr<NesteggPacketHolder> next_holder(NextPacket(aType));
+    RefPtr<NesteggPacketHolder> next_holder;
+    rv = NextPacket(aType, next_holder);
+    if (NS_FAILED(rv) && rv != NS_ERROR_DOM_MEDIA_END_OF_STREAM) {
+      return rv;
+    }
     if (next_holder) {
       next_tstamp = next_holder->Timestamp();
       PushAudioPacket(next_holder);
@@ -593,7 +602,11 @@ WebMDemuxer::GetNextPacket(TrackInfo::TrackType aType, MediaRawDataQueue *aSampl
     }
     mLastAudioFrameTime = Some(tstamp);
   } else if (aType == TrackInfo::kVideoTrack) {
-    RefPtr<NesteggPacketHolder> next_holder(NextPacket(aType));
+    RefPtr<NesteggPacketHolder> next_holder;
+    rv = NextPacket(aType, next_holder);
+    if (NS_FAILED(rv) && rv != NS_ERROR_DOM_MEDIA_END_OF_STREAM) {
+      return rv;
+    }
     if (next_holder) {
       next_tstamp = next_holder->Timestamp();
       PushVideoPacket(next_holder);
@@ -610,7 +623,7 @@ WebMDemuxer::GetNextPacket(TrackInfo::TrackType aType, MediaRawDataQueue *aSampl
   }
 
   if (mIsMediaSource && next_tstamp == INT64_MIN) {
-    return false;
+    return NS_ERROR_DOM_MEDIA_END_OF_STREAM;
   }
 
   int64_t discardPadding = 0;
@@ -626,7 +639,7 @@ WebMDemuxer::GetNextPacket(TrackInfo::TrackType aType, MediaRawDataQueue *aSampl
     r = nestegg_packet_data(holder->Packet(), i, &data, &length);
     if (r == -1) {
       WEBM_DEBUG("nestegg_packet_data failed r=%d", r);
-      return false;
+      return NS_ERROR_DOM_MEDIA_DEMUXER_ERR;
     }
     bool isKeyframe = false;
     if (aType == TrackInfo::kAudioTrack) {
@@ -636,29 +649,46 @@ WebMDemuxer::GetNextPacket(TrackInfo::TrackType aType, MediaRawDataQueue *aSampl
         // Packet is encrypted, can't peek, use packet info
         isKeyframe = nestegg_packet_has_keyframe(holder->Packet()) == NESTEGG_PACKET_HAS_KEYFRAME_TRUE;
       } else {
-        vpx_codec_stream_info_t si;
-        PodZero(&si);
-        si.sz = sizeof(si);
+        auto sample = MakeSpan(data, length);
         switch (mVideoCodec) {
         case NESTEGG_CODEC_VP8:
-          vpx_codec_peek_stream_info(vpx_codec_vp8_dx(), data, length, &si);
+          isKeyframe = VPXDecoder::IsKeyframe(sample, VPXDecoder::Codec::VP8);
           break;
         case NESTEGG_CODEC_VP9:
-          vpx_codec_peek_stream_info(vpx_codec_vp9_dx(), data, length, &si);
+          isKeyframe = VPXDecoder::IsKeyframe(sample, VPXDecoder::Codec::VP9);
+          break;
+#ifdef MOZ_AV1
+        case NESTEGG_CODEC_AV1:
+          isKeyframe = AOMDecoder::IsKeyframe(sample);
           break;
+#endif
+        default:
+          NS_WARNING("Cannot detect keyframes in unknown WebM video codec");
+          return NS_ERROR_FAILURE;
         }
-        isKeyframe = si.is_kf;
         if (isKeyframe) {
-          // We only look for resolution changes on keyframes for both VP8 and
-          // VP9. Other resolution changes are invalid.
-          if (mLastSeenFrameWidth.isSome() && mLastSeenFrameHeight.isSome() &&
-            (si.w != mLastSeenFrameWidth.value() ||
-              si.h != mLastSeenFrameHeight.value())) {
-            mInfo.mVideo.mDisplay = nsIntSize(si.w, si.h);
+          // For both VP8 and VP9, we only look for resolution changes
+          // on keyframes. Other resolution changes are invalid.
+          auto dimensions = nsIntSize(0, 0);
+          switch (mVideoCodec) {
+          case NESTEGG_CODEC_VP8:
+            dimensions = VPXDecoder::GetFrameSize(sample, VPXDecoder::Codec::VP8);
+            break;
+          case NESTEGG_CODEC_VP9:
+            dimensions = VPXDecoder::GetFrameSize(sample, VPXDecoder::Codec::VP9);
+            break;
+#ifdef MOZ_AV1
+          case NESTEGG_CODEC_AV1:
+            dimensions = AOMDecoder::GetFrameSize(sample);
+            break;
+#endif
+          }
+          if (mLastSeenFrameSize.isSome()
+              && (dimensions != mLastSeenFrameSize.value())) {
+            mInfo.mVideo.mDisplay = dimensions;
             mSharedVideoTrackInfo = new SharedTrackInfo(mInfo.mVideo, ++sStreamSourceID);
           }
-          mLastSeenFrameWidth = Some(si.w);
-          mLastSeenFrameHeight = Some(si.h);
+          mLastSeenFrameSize = Some(dimensions);
         }
       }
     }
@@ -668,7 +698,7 @@ WebMDemuxer::GetNextPacket(TrackInfo::TrackType aType, MediaRawDataQueue *aSampl
     RefPtr<MediaRawData> sample = new MediaRawData(data, length);
     if (length && !sample->Data()) {
       // OOM.
-      return false;
+      return NS_ERROR_OUT_OF_MEMORY;
     }
     sample->mTimecode = tstamp;
     sample->mTime = tstamp;
@@ -721,11 +751,12 @@ WebMDemuxer::GetNextPacket(TrackInfo::TrackType aType, MediaRawDataQueue *aSampl
     }
     aSamples->Push(sample);
   }
-  return true;
+  return NS_OK;
 }
 
-RefPtr<NesteggPacketHolder>
-WebMDemuxer::NextPacket(TrackInfo::TrackType aType)
+nsresult
+WebMDemuxer::NextPacket(TrackInfo::TrackType aType,
+                        RefPtr<NesteggPacketHolder>& aPacket)
 {
   bool isVideo = aType == TrackInfo::kVideoTrack;
 
@@ -734,56 +765,64 @@ WebMDemuxer::NextPacket(TrackInfo::TrackType aType)
   bool hasType = isVideo ? mHasVideo : mHasAudio;
 
   if (!hasType) {
-    return nullptr;
+    return NS_ERROR_DOM_MEDIA_DEMUXER_ERR;
   }
 
   // The packet queue for the type that we are interested in.
   WebMPacketQueue &packets = isVideo ? mVideoPackets : mAudioPackets;
 
   if (packets.GetSize() > 0) {
-    return packets.PopFront();
+    aPacket = packets.PopFront();
+    return NS_OK;
   }
 
   // Track we are interested in
   uint32_t ourTrack = isVideo ? mVideoTrack : mAudioTrack;
 
   do {
-    RefPtr<NesteggPacketHolder> holder = DemuxPacket(aType);
+    RefPtr<NesteggPacketHolder> holder;
+    nsresult rv = DemuxPacket(aType, holder);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
     if (!holder) {
-      return nullptr;
+      return NS_ERROR_DOM_MEDIA_DEMUXER_ERR;
     }
 
     if (ourTrack == holder->Track()) {
-      return holder;
+      aPacket = holder;
+      return NS_OK;
     }
   } while (true);
 }
 
-RefPtr<NesteggPacketHolder>
-WebMDemuxer::DemuxPacket(TrackInfo::TrackType aType)
+nsresult
+WebMDemuxer::DemuxPacket(TrackInfo::TrackType aType,
+                         RefPtr<NesteggPacketHolder>& aPacket)
 {
   nestegg_packet* packet;
   int r = nestegg_read_packet(Context(aType), &packet);
   if (r == 0) {
     nestegg_read_reset(Context(aType));
-    return nullptr;
+    return NS_ERROR_DOM_MEDIA_END_OF_STREAM;
   } else if (r < 0) {
-    return nullptr;
+    return NS_ERROR_DOM_MEDIA_DEMUXER_ERR;
   }
 
   unsigned int track = 0;
   r = nestegg_packet_track(packet, &track);
   if (r == -1) {
-    return nullptr;
+    return NS_ERROR_DOM_MEDIA_DEMUXER_ERR;
   }
 
   int64_t offset = Resource(aType).Tell();
   RefPtr<NesteggPacketHolder> holder = new NesteggPacketHolder();
   if (!holder->Init(packet, offset, track, false)) {
-    return nullptr;
+    return NS_ERROR_DOM_MEDIA_DEMUXER_ERR;
   }
 
-  return holder;
+  aPacket = holder;
+  return NS_OK;
 }
 
 void
@@ -943,7 +982,14 @@ WebMTrackDemuxer::Seek(media::TimeUnit aTime)
   media::TimeUnit seekTime = aTime;
   mSamples.Reset();
   mParent->SeekInternal(mType, aTime);
-  mParent->GetNextPacket(mType, &mSamples);
+  nsresult rv = mParent->GetNextPacket(mType, &mSamples);
+  if (NS_FAILED(rv)) {
+    if (rv == NS_ERROR_DOM_MEDIA_END_OF_STREAM) {
+      // Ignore the error for now, the next GetSample will be rejected with EOS.
+      return SeekPromise::CreateAndResolve(media::TimeUnit(), __func__);
+    }
+    return SeekPromise::CreateAndReject(rv, __func__);
+  }
   mNeedKeyframe = true;
 
   // Check what time we actually seeked to.
@@ -956,15 +1002,18 @@ WebMTrackDemuxer::Seek(media::TimeUnit aTime)
   return SeekPromise::CreateAndResolve(seekTime, __func__);
 }
 
-RefPtr<MediaRawData>
-WebMTrackDemuxer::NextSample()
+nsresult
+WebMTrackDemuxer::NextSample(RefPtr<MediaRawData>& aData)
 {
-  while (mSamples.GetSize() < 1 && mParent->GetNextPacket(mType, &mSamples)) {
+  nsresult rv;
+  while (mSamples.GetSize() < 1 &&
+         NS_SUCCEEDED((rv = mParent->GetNextPacket(mType, &mSamples)))) {
   }
   if (mSamples.GetSize()) {
-    return mSamples.PopFront();
+    aData = mSamples.PopFront();
+    return NS_OK;
   }
-  return nullptr;
+  return rv;
 }
 
 RefPtr<WebMTrackDemuxer::SamplesPromise>
@@ -973,9 +1022,12 @@ WebMTrackDemuxer::GetSamples(int32_t aNumSamples)
   RefPtr<SamplesHolder> samples = new SamplesHolder;
   MOZ_ASSERT(aNumSamples);
 
+  nsresult rv = NS_ERROR_DOM_MEDIA_END_OF_STREAM;
+
   while (aNumSamples) {
-    RefPtr<MediaRawData> sample(NextSample());
-    if (!sample) {
+    RefPtr<MediaRawData> sample;
+    rv = NextSample(sample);
+    if (NS_FAILED(rv)) {
       break;
     }
     if (mNeedKeyframe && !sample->mKeyframe) {
@@ -987,7 +1039,7 @@ WebMTrackDemuxer::GetSamples(int32_t aNumSamples)
   }
 
   if (samples->mSamples.IsEmpty()) {
-    return SamplesPromise::CreateAndReject(NS_ERROR_DOM_MEDIA_END_OF_STREAM, __func__);
+    return SamplesPromise::CreateAndReject(rv, __func__);
   } else {
     UpdateSamples(samples->mSamples);
     return SamplesPromise::CreateAndResolve(samples, __func__);
@@ -1022,7 +1074,8 @@ WebMTrackDemuxer::SetNextKeyFrameTime()
   }
   // Demux and buffer frames until we find a keyframe.
   RefPtr<MediaRawData> sample;
-  while (!foundKeyframe && (sample = NextSample())) {
+  nsresult rv = NS_OK;
+  while (!foundKeyframe && NS_SUCCEEDED((rv = NextSample(sample)))) {
     if (sample->mKeyframe) {
       frameTime = sample->mTime;
       foundKeyframe = true;
@@ -1104,10 +1157,11 @@ WebMTrackDemuxer::SkipToNextRandomAccessPoint(media::TimeUnit aTimeThreshold)
   uint32_t parsed = 0;
   bool found = false;
   RefPtr<MediaRawData> sample;
+  nsresult rv = NS_OK;
   int64_t sampleTime;
 
   WEBM_DEBUG("TimeThreshold: %f", aTimeThreshold.ToSeconds());
-  while (!found && (sample = NextSample())) {
+  while (!found && NS_SUCCEEDED((rv = NextSample(sample)))) {
     parsed++;
     sampleTime = sample->mTime;
     if (sample->mKeyframe && sampleTime >= aTimeThreshold.ToMicroseconds()) {
@@ -1116,7 +1170,9 @@ WebMTrackDemuxer::SkipToNextRandomAccessPoint(media::TimeUnit aTimeThreshold)
       mSamples.PushFront(sample.forget());
     }
   }
-  SetNextKeyFrameTime();
+  if (NS_SUCCEEDED(rv)) {
+    SetNextKeyFrameTime();
+  }
   if (found) {
     WEBM_DEBUG("next sample: %f (parsed: %d)",
                media::TimeUnit::FromMicroseconds(sampleTime).ToSeconds(),
diff --git a/dom/media/webm/WebMDemuxer.h b/dom/media/webm/WebMDemuxer.h
index 6fff38e7d..36d381e57 100644
--- a/dom/media/webm/WebMDemuxer.h
+++ b/dom/media/webm/WebMDemuxer.h
@@ -8,9 +8,13 @@
 
 #include "nsTArray.h"
 #include "MediaDataDemuxer.h"
+#include "MediaResource.h"
 #include "NesteggPacketHolder.h"
 #include "mozilla/Move.h"
 
+#include <deque>
+#include <stdint.h>
+
 typedef struct nestegg nestegg;
 
 namespace mozilla {
@@ -111,7 +115,8 @@ public:
   bool GetOffsetForTime(uint64_t aTime, int64_t* aOffset);
 
   // Demux next WebM packet and append samples to MediaRawDataQueue
-  bool GetNextPacket(TrackInfo::TrackType aType, MediaRawDataQueue *aSamples);
+  nsresult GetNextPacket(TrackInfo::TrackType aType,
+                         MediaRawDataQueue *aSamples);
 
   nsresult Reset(TrackInfo::TrackType aType);
 
@@ -175,11 +180,13 @@ private:
   // Read a packet from the nestegg file. Returns nullptr if all packets for
   // the particular track have been read. Pass TrackInfo::kVideoTrack or
   // TrackInfo::kVideoTrack to indicate the type of the packet we want to read.
-  RefPtr<NesteggPacketHolder> NextPacket(TrackInfo::TrackType aType);
+  nsresult NextPacket(TrackInfo::TrackType aType,
+                      RefPtr<NesteggPacketHolder>& aPacket);
 
   // Internal method that demuxes the next packet from the stream. The caller
   // is responsible for making sure it doesn't get lost.
-  RefPtr<NesteggPacketHolder> DemuxPacket(TrackInfo::TrackType aType);
+  nsresult DemuxPacket(TrackInfo::TrackType aType,
+                       RefPtr<NesteggPacketHolder>& aPacket);
 
   // libnestegg audio and video context for webm container.
   // Access on reader's thread only.
@@ -237,8 +244,7 @@ private:
   int64_t mLastWebMBlockOffset;
   const bool mIsMediaSource;
 
-  Maybe<uint32_t> mLastSeenFrameWidth;
-  Maybe<uint32_t> mLastSeenFrameHeight;
+  Maybe<nsIntSize> mLastSeenFrameSize;
   // This will be populated only if a resolution change occurs, otherwise it
   // will be left as null so the original metadata is used
   RefPtr<SharedTrackInfo> mSharedVideoTrackInfo;
@@ -276,7 +282,7 @@ private:
   ~WebMTrackDemuxer();
   void UpdateSamples(nsTArray<RefPtr<MediaRawData>>& aSamples);
   void SetNextKeyFrameTime();
-  RefPtr<MediaRawData> NextSample ();
+  nsresult NextSample(RefPtr<MediaRawData>& aData);
   RefPtr<WebMDemuxer> mParent;
   TrackInfo::TrackType mType;
   UniquePtr<TrackInfo> mInfo;
diff --git a/dom/webidl/CommandEvent.webidl b/dom/webidl/CommandEvent.webidl
index 8c16e856c..9856c77c3 100644
--- a/dom/webidl/CommandEvent.webidl
+++ b/dom/webidl/CommandEvent.webidl
@@ -8,7 +8,7 @@ interface CommandEvent : Event {
   readonly attribute DOMString? command;
 
   void initCommandEvent(DOMString type,
-                        boolean canBubble,
-                        boolean cancelable,
-                        DOMString? command);
+                        optional boolean canBubble = false,
+                        optional boolean cancelable = false,
+                        optional DOMString? command = null);
 };
diff --git a/dom/webidl/CompositionEvent.webidl b/dom/webidl/CompositionEvent.webidl
index c293683ce..e4a54d678 100644
--- a/dom/webidl/CompositionEvent.webidl
+++ b/dom/webidl/CompositionEvent.webidl
@@ -25,9 +25,9 @@ interface CompositionEvent : UIEvent
 partial interface CompositionEvent
 {
   void initCompositionEvent(DOMString typeArg,
-                            boolean canBubbleArg,
-                            boolean cancelableArg,
-                            Window? viewArg,
-                            DOMString? dataArg,
-                            DOMString localeArg);
+                            optional boolean canBubbleArg = false,
+                            optional boolean cancelableArg = false,
+                            optional Window? viewArg = null,
+                            optional DOMString? dataArg = null,
+                            optional DOMString localeArg = "");
 };
diff --git a/dom/webidl/CustomEvent.webidl b/dom/webidl/CustomEvent.webidl
index 299a41ec0..1ea5572b7 100644
--- a/dom/webidl/CustomEvent.webidl
+++ b/dom/webidl/CustomEvent.webidl
@@ -19,9 +19,9 @@ interface CustomEvent : Event
   // initCustomEvent is a Gecko specific deprecated method.
   [Throws]
   void initCustomEvent(DOMString type,
-                       boolean canBubble,
-                       boolean cancelable,
-                       any detail);
+                       optional boolean canBubble = false,
+                       optional boolean cancelable = false,
+                       optional any detail = null);
 };
 
 dictionary CustomEventInit : EventInit
diff --git a/dom/webidl/DeviceMotionEvent.webidl b/dom/webidl/DeviceMotionEvent.webidl
index fa4ecf3ca..c26ab080c 100644
--- a/dom/webidl/DeviceMotionEvent.webidl
+++ b/dom/webidl/DeviceMotionEvent.webidl
@@ -48,10 +48,10 @@ dictionary DeviceMotionEventInit : EventInit {
 // Mozilla extensions.
 partial interface DeviceMotionEvent {
   void initDeviceMotionEvent(DOMString type,
-                             boolean canBubble,
-                             boolean cancelable,
-                             DeviceAccelerationInit acceleration,
-                             DeviceAccelerationInit accelerationIncludingGravity,
-                             DeviceRotationRateInit rotationRate,
-                             double? interval);
+                             optional boolean canBubble = false,
+                             optional boolean cancelable = false,
+                             optional DeviceAccelerationInit acceleration,
+                             optional DeviceAccelerationInit accelerationIncludingGravity,
+                             optional DeviceRotationRateInit rotationRate,
+                             optional double? interval = null);
 };
diff --git a/dom/webidl/DeviceOrientationEvent.webidl b/dom/webidl/DeviceOrientationEvent.webidl
index 46194453e..9802b3681 100644
--- a/dom/webidl/DeviceOrientationEvent.webidl
+++ b/dom/webidl/DeviceOrientationEvent.webidl
@@ -14,12 +14,12 @@ interface DeviceOrientationEvent : Event
 
   // initDeviceOrientationEvent is a Gecko specific deprecated method.
   void initDeviceOrientationEvent(DOMString type,
-                                  boolean canBubble,
-                                  boolean cancelable,
-                                  double? alpha,
-                                  double? beta,
-                                  double? gamma,
-                                  boolean absolute);
+                                  optional boolean canBubble = false,
+                                  optional boolean cancelable = false,
+                                  optional double? alpha = null,
+                                  optional double? beta = null,
+                                  optional double? gamma = null,
+                                  optional boolean absolute = false);
 };
 
 dictionary DeviceOrientationEventInit : EventInit
diff --git a/dom/webidl/DragEvent.webidl b/dom/webidl/DragEvent.webidl
index 2cc173d5c..806177790 100644
--- a/dom/webidl/DragEvent.webidl
+++ b/dom/webidl/DragEvent.webidl
@@ -10,21 +10,21 @@ interface DragEvent : MouseEvent
   readonly attribute DataTransfer? dataTransfer;
 
   void initDragEvent(DOMString type,
-                     boolean canBubble,
-                     boolean cancelable,
-                     Window? aView,
-                     long aDetail,
-                     long aScreenX,
-                     long aScreenY,
-                     long aClientX,
-                     long aClientY,
-                     boolean aCtrlKey,
-                     boolean aAltKey,
-                     boolean aShiftKey,
-                     boolean aMetaKey,
-                     unsigned short aButton,
-                     EventTarget? aRelatedTarget,
-                     DataTransfer? aDataTransfer);
+                     optional boolean canBubble = false,
+                     optional boolean cancelable = false,
+                     optional Window? aView = null,
+                     optional long aDetail = 0,
+                     optional long aScreenX = 0,
+                     optional long aScreenY = 0,
+                     optional long aClientX = 0,
+                     optional long aClientY = 0,
+                     optional boolean aCtrlKey = false,
+                     optional boolean aAltKey = false,
+                     optional boolean aShiftKey = false,
+                     optional boolean aMetaKey = false,
+                     optional unsigned short aButton = 0,
+                     optional EventTarget? aRelatedTarget = null,
+                     optional DataTransfer? aDataTransfer = null);
 };
 
 dictionary DragEventInit : MouseEventInit
diff --git a/dom/webidl/Event.webidl b/dom/webidl/Event.webidl
index 70a0ef513..a5d7da7d4 100644
--- a/dom/webidl/Event.webidl
+++ b/dom/webidl/Event.webidl
@@ -51,7 +51,9 @@ interface Event {
   [Pure]
   readonly attribute DOMHighResTimeStamp timeStamp;
 
-  void initEvent(DOMString type, boolean bubbles, boolean cancelable);
+  void initEvent(DOMString type,
+                 optional boolean bubbles = false,
+                 optional boolean cancelable = false);
   attribute boolean cancelBubble;
 };
 
diff --git a/dom/webidl/HashChangeEvent.webidl b/dom/webidl/HashChangeEvent.webidl
index 735e8eb28..6e8be455c 100644
--- a/dom/webidl/HashChangeEvent.webidl
+++ b/dom/webidl/HashChangeEvent.webidl
@@ -11,10 +11,10 @@ interface HashChangeEvent : Event
   readonly attribute DOMString newURL;
 
   void initHashChangeEvent(DOMString typeArg,
-                           boolean canBubbleArg,
-                           boolean cancelableArg,
-                           DOMString oldURLArg,
-                           DOMString newURLArg);
+                           optional boolean canBubbleArg = false,
+                           optional boolean cancelableArg = false,
+                           optional DOMString oldURLArg = "",
+                           optional DOMString newURLArg = "");
 };
 
 dictionary HashChangeEventInit : EventInit
diff --git a/dom/webidl/KeyEvent.webidl b/dom/webidl/KeyEvent.webidl
index 516632854..abb4b6a34 100644
--- a/dom/webidl/KeyEvent.webidl
+++ b/dom/webidl/KeyEvent.webidl
@@ -225,13 +225,13 @@ interface KeyEvent
   const unsigned long DOM_VK_WIN_OEM_CLEAR  = 0xFE;
 
   void initKeyEvent(DOMString type,
-                    boolean canBubble,
-                    boolean cancelable,
-                    Window? view,
-                    boolean ctrlKey,
-                    boolean altKey,
-                    boolean shiftKey,
-                    boolean metaKey,
-                    unsigned long keyCode,
-                    unsigned long charCode);
+                    optional boolean canBubble = false,
+                    optional boolean cancelable = false,
+                    optional Window? view = null,
+                    optional boolean ctrlKey = false,
+                    optional boolean altKey = false,
+                    optional boolean shiftKey = false,
+                    optional boolean metaKey = false,
+                    optional unsigned long keyCode = 0,
+                    optional unsigned long charCode = 0);
 };
diff --git a/dom/webidl/MessageEvent.webidl b/dom/webidl/MessageEvent.webidl
index 548f14520..be5022d67 100644
--- a/dom/webidl/MessageEvent.webidl
+++ b/dom/webidl/MessageEvent.webidl
@@ -43,10 +43,14 @@ interface MessageEvent : Event {
   [Pure, Cached, Frozen]
   readonly attribute sequence<MessagePort> ports;
 
-  void initMessageEvent(DOMString type, boolean bubbles, boolean cancelable,
-                        any data, DOMString origin, DOMString lastEventId,
-                        (WindowProxy or MessagePort)? source,
-                        sequence<MessagePort> ports);
+  void initMessageEvent(DOMString type,
+                        optional boolean bubbles = false,
+                        optional boolean cancelable = false,
+                        optional any data = null, 
+                        optional DOMString origin = "", 
+                        optional DOMString lastEventId = "",
+                        optional (WindowProxy or MessagePort)? source = null,
+                        optional sequence<MessagePort> ports = []);
 };
 
 dictionary MessageEventInit : EventInit {
diff --git a/dom/webidl/MouseEvent.webidl b/dom/webidl/MouseEvent.webidl
index d21354801..192519d57 100644
--- a/dom/webidl/MouseEvent.webidl
+++ b/dom/webidl/MouseEvent.webidl
@@ -32,21 +32,21 @@ interface MouseEvent : UIEvent {
   readonly attribute long           movementY;
 
   // Deprecated in DOM Level 3:
-  void                              initMouseEvent(DOMString typeArg, 
-                                                   boolean canBubbleArg, 
-                                                   boolean cancelableArg, 
-                                                   Window? viewArg,
-                                                   long detailArg, 
-                                                   long screenXArg, 
-                                                   long screenYArg, 
-                                                   long clientXArg, 
-                                                   long clientYArg, 
-                                                   boolean ctrlKeyArg, 
-                                                   boolean altKeyArg, 
-                                                   boolean shiftKeyArg, 
-                                                   boolean metaKeyArg, 
-                                                   short buttonArg,
-                                                   EventTarget? relatedTargetArg);
+void initMouseEvent(DOMString typeArg,
+                    optional boolean canBubbleArg = false,
+                    optional boolean cancelableArg = false,
+                    optional Window? viewArg = null,
+                    optional long detailArg = 0,
+                    optional long screenXArg = 0,
+                    optional long screenYArg = 0,
+                    optional long clientXArg = 0,
+                    optional long clientYArg = 0,
+                    optional boolean ctrlKeyArg = false,
+                    optional boolean altKeyArg = false,
+                    optional boolean shiftKeyArg = false,
+                    optional boolean metaKeyArg = false,
+                    optional short buttonArg = 0,
+                    optional EventTarget? relatedTargetArg = null);
   // Introduced in DOM Level 3:
   boolean                           getModifierState(DOMString keyArg);
 };
@@ -90,23 +90,23 @@ partial interface MouseEvent
 
   readonly attribute unsigned short mozInputSource;
 
-  void                initNSMouseEvent(DOMString typeArg,
-                                       boolean canBubbleArg,
-                                       boolean cancelableArg,
-                                       Window? viewArg,
-                                       long detailArg,
-                                       long screenXArg,
-                                       long screenYArg,
-                                       long clientXArg,
-                                       long clientYArg,
-                                       boolean ctrlKeyArg,
-                                       boolean altKeyArg,
-                                       boolean shiftKeyArg,
-                                       boolean metaKeyArg,
-                                       short buttonArg,
-                                       EventTarget? relatedTargetArg,
-                                       float pressure,
-                                       unsigned short inputSourceArg);
+  void initNSMouseEvent(DOMString typeArg,
+                        optional boolean canBubbleArg = false,
+                        optional boolean cancelableArg = false,
+                        optional Window? viewArg = null,
+                        optional long detailArg = 0,
+                        optional long screenXArg = 0,
+                        optional long screenYArg = 0,
+                        optional long clientXArg = 0,
+                        optional long clientYArg = 0,
+                        optional boolean ctrlKeyArg = false,
+                        optional boolean altKeyArg = false,
+                        optional boolean shiftKeyArg = false,
+                        optional boolean metaKeyArg = false,
+                        optional short buttonArg = 0,
+                        optional EventTarget? relatedTargetArg = null,
+                        optional float pressure = 0,
+                        optional unsigned short inputSourceArg = 0);
   [ChromeOnly]
   readonly attribute boolean hitCluster; // True when touch occurs in a cluster of links
 
diff --git a/dom/webidl/MouseScrollEvent.webidl b/dom/webidl/MouseScrollEvent.webidl
index aa9e30fd2..c1e52bd8c 100644
--- a/dom/webidl/MouseScrollEvent.webidl
+++ b/dom/webidl/MouseScrollEvent.webidl
@@ -12,19 +12,19 @@ interface MouseScrollEvent : MouseEvent
   readonly attribute long axis;
 
   void initMouseScrollEvent(DOMString type,
-                            boolean canBubble,
-                            boolean cancelable,
-                            Window? view,
-                            long detail,
-                            long screenX,
-                            long screenY,
-                            long clientX,
-                            long clientY,
-                            boolean ctrlKey,
-                            boolean altKey,
-                            boolean shiftKey,
-                            boolean metaKey,
-                            unsigned short button,
-                            EventTarget? relatedTarget,
-                            long axis);
+                            optional boolean canBubble = false,
+                            optional boolean cancelable = false,
+                            optional Window? view = null,
+                            optional long detail = 0,
+                            optional long screenX = 0,
+                            optional long screenY = 0,
+                            optional long clientX = 0,
+                            optional long clientY = 0,
+                            optional boolean ctrlKey = false,
+                            optional boolean altKey = false,
+                            optional boolean shiftKey = false,
+                            optional boolean metaKey = false,
+                            optional short button = 0,
+                            optional EventTarget? relatedTarget = null,
+                            optional long axis = 0);
 };
diff --git a/dom/webidl/MutationEvent.webidl b/dom/webidl/MutationEvent.webidl
index 43c7b1cd0..53625b4f9 100644
--- a/dom/webidl/MutationEvent.webidl
+++ b/dom/webidl/MutationEvent.webidl
@@ -23,11 +23,11 @@ interface MutationEvent : Event
 
   [Throws]
   void initMutationEvent(DOMString type,
-                         boolean canBubble,
-                         boolean cancelable,
-                         Node? relatedNode,
-                         DOMString prevValue,
-                         DOMString newValue,
-                         DOMString attrName,
-                         unsigned short attrChange);
+                         optional boolean canBubble = false,
+                         optional boolean cancelable = false,
+                         optional Node? relatedNode = null,
+                         optional DOMString prevValue = "",
+                         optional DOMString newValue = "",
+                         optional DOMString attrName = "",
+                         optional unsigned short attrChange = 0);
 };
diff --git a/dom/webidl/ScrollAreaEvent.webidl b/dom/webidl/ScrollAreaEvent.webidl
index 0f48b4bc8..f24b7c0ad 100644
--- a/dom/webidl/ScrollAreaEvent.webidl
+++ b/dom/webidl/ScrollAreaEvent.webidl
@@ -12,12 +12,12 @@ interface ScrollAreaEvent : UIEvent
   readonly attribute float height;
 
   void initScrollAreaEvent(DOMString type,
-                           boolean canBubble,
-                           boolean cancelable,
-                           Window? view,
-                           long detail,
-                           float x,
-                           float y,
-                           float width,
-                           float height);
+                           optional boolean canBubble = false,
+                           optional boolean cancelable = false,
+                           optional Window? view = null,
+                           optional long detail = 0,
+                           optional float x = 0,
+                           optional float y = 0,
+                           optional float width = 0,
+                           optional float height = 0);
 };
diff --git a/dom/webidl/SimpleGestureEvent.webidl b/dom/webidl/SimpleGestureEvent.webidl
index 0829076dd..76d0d20f6 100644
--- a/dom/webidl/SimpleGestureEvent.webidl
+++ b/dom/webidl/SimpleGestureEvent.webidl
@@ -25,22 +25,22 @@ interface SimpleGestureEvent : MouseEvent
   readonly attribute unsigned long clickCount;
 
   void initSimpleGestureEvent(DOMString typeArg,
-                              boolean canBubbleArg,
-                              boolean cancelableArg,
-                              Window? viewArg,
-                              long detailArg,
-                              long screenXArg,
-                              long screenYArg,
-                              long clientXArg,
-                              long clientYArg,
-                              boolean ctrlKeyArg,
-                              boolean altKeyArg,
-                              boolean shiftKeyArg,
-                              boolean metaKeyArg,
-                              unsigned short buttonArg,
-                              EventTarget? relatedTargetArg,
-                              unsigned long allowedDirectionsArg,
-                              unsigned long directionArg,
-                              double deltaArg,
-                              unsigned long clickCount);
+                              optional boolean canBubbleArg = false,
+                              optional boolean cancelableArg = false,
+                              optional Window? viewArg = null,
+                              optional long detailArg = 0,
+                              optional long screenXArg = 0,
+                              optional long screenYArg = 0,
+                              optional long clientXArg = 0,
+                              optional long clientYArg = 0,
+                              optional boolean ctrlKeyArg = false,
+                              optional boolean altKeyArg = false,
+                              optional boolean shiftKeyArg = false,
+                              optional boolean metaKeyArg = false,
+                              optional short buttonArg = 0,
+                              optional EventTarget? relatedTargetArg = null,
+                              optional unsigned long allowedDirectionsArg = 0,
+                              optional unsigned long directionArg = 0,
+                              optional double deltaArg = 0,
+                              optional unsigned long clickCount = 0);
 };
diff --git a/dom/webidl/StorageEvent.webidl b/dom/webidl/StorageEvent.webidl
index c3e9605eb..e03f8232c 100644
--- a/dom/webidl/StorageEvent.webidl
+++ b/dom/webidl/StorageEvent.webidl
@@ -21,13 +21,13 @@ interface StorageEvent : Event
 
   // Bug 1016053 - This is not spec compliant.
   void initStorageEvent(DOMString type,
-                        boolean canBubble,
-                        boolean cancelable,
-                        DOMString? key,
-                        DOMString? oldValue,
-                        DOMString? newValue,
-                        DOMString? url,
-                        Storage? storageArea);
+                        optional boolean canBubble = false,
+                        optional boolean cancelable = false,
+                        optional DOMString? key = null,
+                        optional DOMString? oldValue = null,
+                        optional DOMString? newValue = null,
+                        optional DOMString? url = null,
+                        optional Storage? storageArea = null);
 };
 
 dictionary StorageEventInit : EventInit
diff --git a/dom/webidl/TimeEvent.webidl b/dom/webidl/TimeEvent.webidl
index 40e7a0beb..8bbe4db53 100644
--- a/dom/webidl/TimeEvent.webidl
+++ b/dom/webidl/TimeEvent.webidl
@@ -15,6 +15,6 @@ interface TimeEvent : Event
   readonly attribute long         detail;
   readonly attribute WindowProxy? view;
   void initTimeEvent(DOMString aType,
-                     Window? aView,
-                     long aDetail);
+                     optional Window? aView = null,
+                     optional long aDetail = 0);
 };
diff --git a/dom/webidl/TouchEvent.webidl b/dom/webidl/TouchEvent.webidl
index d206fe0fb..fd677787a 100644
--- a/dom/webidl/TouchEvent.webidl
+++ b/dom/webidl/TouchEvent.webidl
@@ -23,15 +23,15 @@ interface TouchEvent : UIEvent {
   readonly attribute boolean shiftKey;
 
   void initTouchEvent(DOMString type,
-                      boolean canBubble,
-                      boolean cancelable,
-                      Window? view,
-                      long detail,
-                      boolean ctrlKey,
-                      boolean altKey,
-                      boolean shiftKey,
-                      boolean metaKey,
-                      TouchList? touches,
-                      TouchList? targetTouches,
-                      TouchList? changedTouches);
+                      optional boolean canBubble = false,
+                      optional boolean cancelable = false,
+                      optional Window? view = null,
+                      optional long detail = 0,
+                      optional boolean ctrlKey = false,
+                      optional boolean altKey = false,
+                      optional boolean shiftKey = false,
+                      optional boolean metaKey = false,
+                      optional TouchList? touches = null,
+                      optional TouchList? targetTouches = null,
+                      optional TouchList? changedTouches = null);
 };
diff --git a/dom/webidl/UIEvent.webidl b/dom/webidl/UIEvent.webidl
index 9cc1d0cdf..5be6a443a 100644
--- a/dom/webidl/UIEvent.webidl
+++ b/dom/webidl/UIEvent.webidl
@@ -16,10 +16,10 @@ interface UIEvent : Event
   readonly attribute WindowProxy? view;
   readonly attribute long         detail;
   void initUIEvent(DOMString aType,
-                   boolean aCanBubble,
-                   boolean aCancelable,
-                   Window? aView,
-                   long aDetail);
+                   optional boolean aCanBubble = false,
+                   optional boolean aCancelable = false,
+                   optional Window? aView = null,
+                   optional long aDetail = 0);
 };
 
 // Additional DOM0 properties.
diff --git a/dom/webidl/XULCommandEvent.webidl b/dom/webidl/XULCommandEvent.webidl
index 9c024edc1..72dc3802e 100644
--- a/dom/webidl/XULCommandEvent.webidl
+++ b/dom/webidl/XULCommandEvent.webidl
@@ -15,13 +15,13 @@ interface XULCommandEvent : UIEvent
   readonly attribute Event? sourceEvent;
 
   void initCommandEvent(DOMString type,
-                        boolean canBubble,
-                        boolean cancelable,
-                        Window? view,
-                        long detail,
-                        boolean ctrlKey,
-                        boolean altKey,
-                        boolean shiftKey,
-                        boolean metaKey,
-                        Event? sourceEvent);
+                        optional boolean canBubble = false,
+                        optional boolean cancelable = false,
+                        optional Window? view = null,
+                        optional long detail = 0,
+                        optional boolean ctrlKey = false,
+                        optional boolean altKey = false,
+                        optional boolean shiftKey = false,
+                        optional boolean metaKey = false,
+                        optional Event? sourceEvent = null);
 };
diff --git a/dom/xbl/nsXBLBinding.cpp b/dom/xbl/nsXBLBinding.cpp
index d9a2aacc5..b8174f6c2 100644
--- a/dom/xbl/nsXBLBinding.cpp
+++ b/dom/xbl/nsXBLBinding.cpp
@@ -1049,7 +1049,8 @@ nsXBLBinding::DoInitJSClass(JSContext *cx,
   // to create and define it.
   JS::Rooted<JSObject*> proto(cx);
   JS::Rooted<JS::PropertyDescriptor> desc(cx);
-  if (!JS_GetOwnUCPropertyDescriptor(cx, holder, aClassName.get(), &desc)) {
+  if (!JS_GetOwnUCPropertyDescriptor(cx, holder, aClassName.get(),
+                                     aClassName.Length(), &desc)) {
     return NS_ERROR_OUT_OF_MEMORY;
   }
   *aNew = !desc.object();
diff --git a/dom/xbl/nsXBLProtoImpl.cpp b/dom/xbl/nsXBLProtoImpl.cpp
index 4db9cabf0..5efcb71e0 100644
--- a/dom/xbl/nsXBLProtoImpl.cpp
+++ b/dom/xbl/nsXBLProtoImpl.cpp
@@ -100,11 +100,15 @@ nsXBLProtoImpl::InstallImplementation(nsXBLPrototypeBinding* aPrototypeBinding,
   // end up with a different content prototype, but we'll already have a property
   // holder called |foo| in the XBL scope. Check for that to avoid wasteful and
   // weird property holder duplication.
-  const char16_t* className = aPrototypeBinding->ClassName().get();
+  const nsString& className = aPrototypeBinding->ClassName();
+  const char16_t* classNameChars = className.get();
+  const size_t classNameLen = className.Length();
+
   JS::Rooted<JSObject*> propertyHolder(cx);
   JS::Rooted<JS::PropertyDescriptor> existingHolder(cx);
   if (scopeObject != globalObject &&
-      !JS_GetOwnUCPropertyDescriptor(cx, scopeObject, className, &existingHolder)) {
+      !JS_GetOwnUCPropertyDescriptor(cx, scopeObject, classNameChars,
+                                     classNameLen, &existingHolder)) {
     return NS_ERROR_FAILURE;
   }
   bool propertyHolderIsNew = !existingHolder.object() || !existingHolder.value().isObject();
@@ -119,8 +123,8 @@ nsXBLProtoImpl::InstallImplementation(nsXBLPrototypeBinding* aPrototypeBinding,
 
     // Define it as a property on the scopeObject, using the same name used on
     // the content side.
-    bool ok = JS_DefineUCProperty(cx, scopeObject, className, -1, propertyHolder,
-                                  JSPROP_PERMANENT | JSPROP_READONLY,
+    bool ok = JS_DefineUCProperty(cx, scopeObject, classNameChars, classNameLen,
+                                  propertyHolder, JSPROP_PERMANENT | JSPROP_READONLY,
                                   JS_STUBGETTER, JS_STUBSETTER);
     NS_ENSURE_TRUE(ok, NS_ERROR_UNEXPECTED);
   } else {