Add m-esr52 at 52.6.0

1 files changed, 2505 insertions, 0 deletions

diff --git a/gfx/layers/Layers.cpp b/gfx/layers/Layers.cpp
new file mode 100644
index 000000000..ff5ab9b50
--- /dev/null
+++ b/gfx/layers/Layers.cpp
@@ -0,0 +1,2505 @@
+/* -*- 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 "Layers.h"
+#include <algorithm>                    // for max, min
+#include "apz/src/AsyncPanZoomController.h"
+#include "CompositableHost.h"           // for CompositableHost
+#include "ImageContainer.h"             // for ImageContainer, etc
+#include "ImageLayers.h"                // for ImageLayer
+#include "LayerSorter.h"                // for SortLayersBy3DZOrder
+#include "LayersLogging.h"              // for AppendToString
+#include "LayerUserData.h"
+#include "ReadbackLayer.h"              // for ReadbackLayer
+#include "UnitTransforms.h"             // for ViewAs
+#include "gfxEnv.h"
+#include "gfxPlatform.h"                // for gfxPlatform
+#include "gfxPrefs.h"
+#include "gfxUtils.h"                   // for gfxUtils, etc
+#include "gfx2DGlue.h"
+#include "mozilla/DebugOnly.h"          // for DebugOnly
+#include "mozilla/Telemetry.h"          // for Accumulate
+#include "mozilla/ToString.h"
+#include "mozilla/dom/Animation.h"      // for ComputedTimingFunction
+#include "mozilla/gfx/2D.h"             // for DrawTarget
+#include "mozilla/gfx/BaseSize.h"       // for BaseSize
+#include "mozilla/gfx/Matrix.h"         // for Matrix4x4
+#include "mozilla/layers/AsyncCanvasRenderer.h"
+#include "mozilla/layers/CompositableClient.h"  // for CompositableClient
+#include "mozilla/layers/Compositor.h"  // for Compositor
+#include "mozilla/layers/CompositorTypes.h"
+#include "mozilla/layers/LayerAnimationUtils.h"  // for TimingFunctionToComputedTimingFunction
+#include "mozilla/layers/LayerManagerComposite.h"  // for LayerComposite
+#include "mozilla/layers/LayerMetricsWrapper.h" // for LayerMetricsWrapper
+#include "mozilla/layers/LayersMessages.h"  // for TransformFunction, etc
+#include "mozilla/layers/LayersTypes.h"  // for TextureDumpMode
+#include "mozilla/layers/PersistentBufferProvider.h"
+#include "mozilla/layers/ShadowLayers.h"  // for ShadowableLayer
+#include "nsAString.h"
+#include "nsCSSValue.h"                 // for nsCSSValue::Array, etc
+#include "nsPrintfCString.h"            // for nsPrintfCString
+#include "nsStyleStruct.h"              // for nsTimingFunction, etc
+#include "protobuf/LayerScopePacket.pb.h"
+#include "mozilla/Compression.h"
+#include "TreeTraversal.h"              // for ForEachNode
+
+uint8_t gLayerManagerLayerBuilder;
+
+namespace mozilla {
+namespace layers {
+
+FILE*
+FILEOrDefault(FILE* aFile)
+{
+  return aFile ? aFile : stderr;
+}
+
+typedef FrameMetrics::ViewID ViewID;
+
+using namespace mozilla::gfx;
+using namespace mozilla::Compression;
+
+//--------------------------------------------------
+// LayerManager
+
+/* static */ mozilla::LogModule*
+LayerManager::GetLog()
+{
+  static LazyLogModule sLog("Layers");
+  return sLog;
+}
+
+FrameMetrics::ViewID
+LayerManager::GetRootScrollableLayerId()
+{
+  if (!mRoot) {
+    return FrameMetrics::NULL_SCROLL_ID;
+  }
+
+  LayerMetricsWrapper layerMetricsRoot = LayerMetricsWrapper(mRoot);
+
+  LayerMetricsWrapper rootScrollableLayerMetrics =
+      BreadthFirstSearch<ForwardIterator>(
+          layerMetricsRoot,
+          [](LayerMetricsWrapper aLayerMetrics)
+          {
+            return aLayerMetrics.Metrics().IsScrollable();
+          }
+      );
+
+  return rootScrollableLayerMetrics.IsValid() ?
+      rootScrollableLayerMetrics.Metrics().GetScrollId() :
+      FrameMetrics::NULL_SCROLL_ID;
+}
+
+LayerMetricsWrapper
+LayerManager::GetRootContentLayer()
+{
+  if (!mRoot) {
+    return LayerMetricsWrapper();
+  }
+
+  LayerMetricsWrapper root(mRoot);
+
+  return BreadthFirstSearch<ForwardIterator>(root,
+      [](LayerMetricsWrapper aLayerMetrics)
+      {
+        return aLayerMetrics.Metrics().IsRootContent();
+      }
+  );
+}
+
+already_AddRefed<DrawTarget>
+LayerManager::CreateOptimalDrawTarget(const gfx::IntSize &aSize,
+                                      SurfaceFormat aFormat)
+{
+  return gfxPlatform::GetPlatform()->CreateOffscreenContentDrawTarget(aSize,
+                                                                      aFormat);
+}
+
+already_AddRefed<DrawTarget>
+LayerManager::CreateOptimalMaskDrawTarget(const gfx::IntSize &aSize)
+{
+  return CreateOptimalDrawTarget(aSize, SurfaceFormat::A8);
+}
+
+already_AddRefed<DrawTarget>
+LayerManager::CreateDrawTarget(const IntSize &aSize,
+                               SurfaceFormat aFormat)
+{
+  return gfxPlatform::GetPlatform()->
+    CreateOffscreenCanvasDrawTarget(aSize, aFormat);
+}
+
+already_AddRefed<PersistentBufferProvider>
+LayerManager::CreatePersistentBufferProvider(const mozilla::gfx::IntSize &aSize,
+                                             mozilla::gfx::SurfaceFormat aFormat)
+{
+  RefPtr<PersistentBufferProviderBasic> bufferProvider =
+    PersistentBufferProviderBasic::Create(aSize, aFormat,
+      gfxPlatform::GetPlatform()->GetPreferredCanvasBackend());
+
+  if (!bufferProvider) {
+    bufferProvider = PersistentBufferProviderBasic::Create(aSize, aFormat,
+      gfxPlatform::GetPlatform()->GetFallbackCanvasBackend());
+  }
+
+  return bufferProvider.forget();
+}
+
+#ifdef DEBUG
+void
+LayerManager::Mutated(Layer* aLayer)
+{
+}
+#endif  // DEBUG
+
+already_AddRefed<ImageContainer>
+LayerManager::CreateImageContainer(ImageContainer::Mode flag)
+{
+  RefPtr<ImageContainer> container = new ImageContainer(flag);
+  return container.forget();
+}
+
+bool
+LayerManager::AreComponentAlphaLayersEnabled()
+{
+  return gfxPrefs::ComponentAlphaEnabled();
+}
+
+/*static*/ void
+LayerManager::LayerUserDataDestroy(void* data)
+{
+  delete static_cast<LayerUserData*>(data);
+}
+
+UniquePtr<LayerUserData>
+LayerManager::RemoveUserData(void* aKey)
+{
+  UniquePtr<LayerUserData> d(static_cast<LayerUserData*>(mUserData.Remove(static_cast<gfx::UserDataKey*>(aKey))));
+  return d;
+}
+
+//--------------------------------------------------
+// Layer
+
+Layer::Layer(LayerManager* aManager, void* aImplData) :
+  mManager(aManager),
+  mParent(nullptr),
+  mNextSibling(nullptr),
+  mPrevSibling(nullptr),
+  mImplData(aImplData),
+  mMaskLayer(nullptr),
+  mPostXScale(1.0f),
+  mPostYScale(1.0f),
+  mOpacity(1.0),
+  mMixBlendMode(CompositionOp::OP_OVER),
+  mForceIsolatedGroup(false),
+  mContentFlags(0),
+  mUseTileSourceRect(false),
+  mIsFixedPosition(false),
+  mTransformIsPerspective(false),
+  mFixedPositionData(nullptr),
+  mStickyPositionData(nullptr),
+  mScrollbarTargetId(FrameMetrics::NULL_SCROLL_ID),
+  mScrollbarDirection(ScrollDirection::NONE),
+  mScrollbarThumbRatio(0.0f),
+  mIsScrollbarContainer(false),
+#ifdef DEBUG
+  mDebugColorIndex(0),
+#endif
+  mAnimationGeneration(0)
+{
+  MOZ_COUNT_CTOR(Layer);
+}
+
+Layer::~Layer()
+{
+  MOZ_COUNT_DTOR(Layer);
+}
+
+Animation*
+Layer::AddAnimation()
+{
+  MOZ_LAYERS_LOG_IF_SHADOWABLE(this, ("Layer::Mutated(%p) AddAnimation", this));
+
+  MOZ_ASSERT(!mPendingAnimations, "should have called ClearAnimations first");
+
+  Animation* anim = mAnimations.AppendElement();
+
+  Mutated();
+  return anim;
+}
+
+void
+Layer::ClearAnimations()
+{
+  mPendingAnimations = nullptr;
+
+  if (mAnimations.IsEmpty() && mAnimationData.IsEmpty()) {
+    return;
+  }
+
+  MOZ_LAYERS_LOG_IF_SHADOWABLE(this, ("Layer::Mutated(%p) ClearAnimations", this));
+  mAnimations.Clear();
+  mAnimationData.Clear();
+  Mutated();
+}
+
+Animation*
+Layer::AddAnimationForNextTransaction()
+{
+  MOZ_ASSERT(mPendingAnimations,
+             "should have called ClearAnimationsForNextTransaction first");
+
+  Animation* anim = mPendingAnimations->AppendElement();
+
+  return anim;
+}
+
+void
+Layer::ClearAnimationsForNextTransaction()
+{
+  // Ensure we have a non-null mPendingAnimations to mark a future clear.
+  if (!mPendingAnimations) {
+    mPendingAnimations = new AnimationArray;
+  }
+
+  mPendingAnimations->Clear();
+}
+
+static inline void
+SetCSSAngle(const CSSAngle& aAngle, nsCSSValue& aValue)
+{
+  aValue.SetFloatValue(aAngle.value(), nsCSSUnit(aAngle.unit()));
+}
+
+static nsCSSValueSharedList*
+CreateCSSValueList(const InfallibleTArray<TransformFunction>& aFunctions)
+{
+  nsAutoPtr<nsCSSValueList> result;
+  nsCSSValueList** resultTail = getter_Transfers(result);
+  for (uint32_t i = 0; i < aFunctions.Length(); i++) {
+    RefPtr<nsCSSValue::Array> arr;
+    switch (aFunctions[i].type()) {
+      case TransformFunction::TRotationX:
+      {
+        const CSSAngle& angle = aFunctions[i].get_RotationX().angle();
+        arr = StyleAnimationValue::AppendTransformFunction(eCSSKeyword_rotatex,
+                                                           resultTail);
+        SetCSSAngle(angle, arr->Item(1));
+        break;
+      }
+      case TransformFunction::TRotationY:
+      {
+        const CSSAngle& angle = aFunctions[i].get_RotationY().angle();
+        arr = StyleAnimationValue::AppendTransformFunction(eCSSKeyword_rotatey,
+                                                           resultTail);
+        SetCSSAngle(angle, arr->Item(1));
+        break;
+      }
+      case TransformFunction::TRotationZ:
+      {
+        const CSSAngle& angle = aFunctions[i].get_RotationZ().angle();
+        arr = StyleAnimationValue::AppendTransformFunction(eCSSKeyword_rotatez,
+                                                           resultTail);
+        SetCSSAngle(angle, arr->Item(1));
+        break;
+      }
+      case TransformFunction::TRotation:
+      {
+        const CSSAngle& angle = aFunctions[i].get_Rotation().angle();
+        arr = StyleAnimationValue::AppendTransformFunction(eCSSKeyword_rotate,
+                                                           resultTail);
+        SetCSSAngle(angle, arr->Item(1));
+        break;
+      }
+      case TransformFunction::TRotation3D:
+      {
+        float x = aFunctions[i].get_Rotation3D().x();
+        float y = aFunctions[i].get_Rotation3D().y();
+        float z = aFunctions[i].get_Rotation3D().z();
+        const CSSAngle& angle = aFunctions[i].get_Rotation3D().angle();
+        arr =
+          StyleAnimationValue::AppendTransformFunction(eCSSKeyword_rotate3d,
+                                                       resultTail);
+        arr->Item(1).SetFloatValue(x, eCSSUnit_Number);
+        arr->Item(2).SetFloatValue(y, eCSSUnit_Number);
+        arr->Item(3).SetFloatValue(z, eCSSUnit_Number);
+        SetCSSAngle(angle, arr->Item(4));
+        break;
+      }
+      case TransformFunction::TScale:
+      {
+        arr =
+          StyleAnimationValue::AppendTransformFunction(eCSSKeyword_scale3d,
+                                                       resultTail);
+        arr->Item(1).SetFloatValue(aFunctions[i].get_Scale().x(), eCSSUnit_Number);
+        arr->Item(2).SetFloatValue(aFunctions[i].get_Scale().y(), eCSSUnit_Number);
+        arr->Item(3).SetFloatValue(aFunctions[i].get_Scale().z(), eCSSUnit_Number);
+        break;
+      }
+      case TransformFunction::TTranslation:
+      {
+        arr =
+          StyleAnimationValue::AppendTransformFunction(eCSSKeyword_translate3d,
+                                                       resultTail);
+        arr->Item(1).SetFloatValue(aFunctions[i].get_Translation().x(), eCSSUnit_Pixel);
+        arr->Item(2).SetFloatValue(aFunctions[i].get_Translation().y(), eCSSUnit_Pixel);
+        arr->Item(3).SetFloatValue(aFunctions[i].get_Translation().z(), eCSSUnit_Pixel);
+        break;
+      }
+      case TransformFunction::TSkewX:
+      {
+        const CSSAngle& x = aFunctions[i].get_SkewX().x();
+        arr = StyleAnimationValue::AppendTransformFunction(eCSSKeyword_skewx,
+                                                           resultTail);
+        SetCSSAngle(x, arr->Item(1));
+        break;
+      }
+      case TransformFunction::TSkewY:
+      {
+        const CSSAngle& y = aFunctions[i].get_SkewY().y();
+        arr = StyleAnimationValue::AppendTransformFunction(eCSSKeyword_skewy,
+                                                           resultTail);
+        SetCSSAngle(y, arr->Item(1));
+        break;
+      }
+      case TransformFunction::TSkew:
+      {
+        const CSSAngle& x = aFunctions[i].get_Skew().x();
+        const CSSAngle& y = aFunctions[i].get_Skew().y();
+        arr = StyleAnimationValue::AppendTransformFunction(eCSSKeyword_skew,
+                                                           resultTail);
+        SetCSSAngle(x, arr->Item(1));
+        SetCSSAngle(y, arr->Item(2));
+        break;
+      }
+      case TransformFunction::TTransformMatrix:
+      {
+        arr =
+          StyleAnimationValue::AppendTransformFunction(eCSSKeyword_matrix3d,
+                                                       resultTail);
+        const gfx::Matrix4x4& matrix = aFunctions[i].get_TransformMatrix().value();
+        arr->Item(1).SetFloatValue(matrix._11, eCSSUnit_Number);
+        arr->Item(2).SetFloatValue(matrix._12, eCSSUnit_Number);
+        arr->Item(3).SetFloatValue(matrix._13, eCSSUnit_Number);
+        arr->Item(4).SetFloatValue(matrix._14, eCSSUnit_Number);
+        arr->Item(5).SetFloatValue(matrix._21, eCSSUnit_Number);
+        arr->Item(6).SetFloatValue(matrix._22, eCSSUnit_Number);
+        arr->Item(7).SetFloatValue(matrix._23, eCSSUnit_Number);
+        arr->Item(8).SetFloatValue(matrix._24, eCSSUnit_Number);
+        arr->Item(9).SetFloatValue(matrix._31, eCSSUnit_Number);
+        arr->Item(10).SetFloatValue(matrix._32, eCSSUnit_Number);
+        arr->Item(11).SetFloatValue(matrix._33, eCSSUnit_Number);
+        arr->Item(12).SetFloatValue(matrix._34, eCSSUnit_Number);
+        arr->Item(13).SetFloatValue(matrix._41, eCSSUnit_Number);
+        arr->Item(14).SetFloatValue(matrix._42, eCSSUnit_Number);
+        arr->Item(15).SetFloatValue(matrix._43, eCSSUnit_Number);
+        arr->Item(16).SetFloatValue(matrix._44, eCSSUnit_Number);
+        break;
+      }
+      case TransformFunction::TPerspective:
+      {
+        float perspective = aFunctions[i].get_Perspective().value();
+        arr =
+          StyleAnimationValue::AppendTransformFunction(eCSSKeyword_perspective,
+                                                       resultTail);
+        arr->Item(1).SetFloatValue(perspective, eCSSUnit_Pixel);
+        break;
+      }
+      default:
+        NS_ASSERTION(false, "All functions should be implemented?");
+    }
+  }
+  if (aFunctions.Length() == 0) {
+    result = new nsCSSValueList();
+    result->mValue.SetNoneValue();
+  }
+  return new nsCSSValueSharedList(result.forget());
+}
+
+void
+Layer::SetAnimations(const AnimationArray& aAnimations)
+{
+  MOZ_LAYERS_LOG_IF_SHADOWABLE(this, ("Layer::Mutated(%p) SetAnimations", this));
+
+  mAnimations = aAnimations;
+  mAnimationData.Clear();
+  for (uint32_t i = 0; i < mAnimations.Length(); i++) {
+    Animation& animation = mAnimations[i];
+    // Adjust fill mode to fill forwards so that if the main thread is delayed
+    // in clearing this animation we don't introduce flicker by jumping back to
+    // the old underlying value
+    switch (static_cast<dom::FillMode>(animation.fillMode())) {
+      case dom::FillMode::None:
+        animation.fillMode() = static_cast<uint8_t>(dom::FillMode::Forwards);
+        break;
+      case dom::FillMode::Backwards:
+        animation.fillMode() = static_cast<uint8_t>(dom::FillMode::Both);
+        break;
+      default:
+        break;
+    }
+
+    AnimData* data = mAnimationData.AppendElement();
+    InfallibleTArray<Maybe<ComputedTimingFunction>>& functions =
+      data->mFunctions;
+    const InfallibleTArray<AnimationSegment>& segments = animation.segments();
+    for (uint32_t j = 0; j < segments.Length(); j++) {
+      TimingFunction tf = segments.ElementAt(j).sampleFn();
+
+      Maybe<ComputedTimingFunction> ctf =
+        AnimationUtils::TimingFunctionToComputedTimingFunction(tf);
+      functions.AppendElement(ctf);
+    }
+
+    // Precompute the StyleAnimationValues that we need if this is a transform
+    // animation.
+    InfallibleTArray<StyleAnimationValue>& startValues = data->mStartValues;
+    InfallibleTArray<StyleAnimationValue>& endValues = data->mEndValues;
+    for (uint32_t j = 0; j < segments.Length(); j++) {
+      const AnimationSegment& segment = segments[j];
+      StyleAnimationValue* startValue = startValues.AppendElement();
+      StyleAnimationValue* endValue = endValues.AppendElement();
+      if (segment.endState().type() == Animatable::TArrayOfTransformFunction) {
+        const InfallibleTArray<TransformFunction>& startFunctions =
+          segment.startState().get_ArrayOfTransformFunction();
+        startValue->SetTransformValue(CreateCSSValueList(startFunctions));
+
+        const InfallibleTArray<TransformFunction>& endFunctions =
+          segment.endState().get_ArrayOfTransformFunction();
+        endValue->SetTransformValue(CreateCSSValueList(endFunctions));
+      } else {
+        NS_ASSERTION(segment.endState().type() == Animatable::Tfloat,
+                     "Unknown Animatable type");
+        startValue->SetFloatValue(segment.startState().get_float());
+        endValue->SetFloatValue(segment.endState().get_float());
+      }
+    }
+  }
+
+  Mutated();
+}
+
+void
+Layer::StartPendingAnimations(const TimeStamp& aReadyTime)
+{
+  ForEachNode<ForwardIterator>(
+      this,
+      [&aReadyTime](Layer *layer)
+      {
+        bool updated = false;
+        for (size_t animIdx = 0, animEnd = layer->mAnimations.Length();
+             animIdx < animEnd; animIdx++) {
+          Animation& anim = layer->mAnimations[animIdx];
+          if (anim.startTime().IsNull()) {
+            anim.startTime() = aReadyTime - anim.initialCurrentTime();
+            updated = true;
+          }
+        }
+        if (updated) {
+          layer->Mutated();
+        }
+      });
+}
+
+void
+Layer::SetAsyncPanZoomController(uint32_t aIndex, AsyncPanZoomController *controller)
+{
+  MOZ_ASSERT(aIndex < GetScrollMetadataCount());
+  mApzcs[aIndex] = controller;
+}
+
+AsyncPanZoomController*
+Layer::GetAsyncPanZoomController(uint32_t aIndex) const
+{
+  MOZ_ASSERT(aIndex < GetScrollMetadataCount());
+#ifdef DEBUG
+  if (mApzcs[aIndex]) {
+    MOZ_ASSERT(GetFrameMetrics(aIndex).IsScrollable());
+  }
+#endif
+  return mApzcs[aIndex];
+}
+
+void
+Layer::ScrollMetadataChanged()
+{
+  mApzcs.SetLength(GetScrollMetadataCount());
+}
+
+void
+Layer::ApplyPendingUpdatesToSubtree()
+{
+  ForEachNode<ForwardIterator>(
+      this,
+      [] (Layer *layer)
+      {
+        layer->ApplyPendingUpdatesForThisTransaction();
+      });
+
+  // Once we're done recursing through the whole tree, clear the pending
+  // updates from the manager.
+  Manager()->ClearPendingScrollInfoUpdate();
+}
+
+bool
+Layer::IsOpaqueForVisibility()
+{
+  return GetEffectiveOpacity() == 1.0f &&
+         GetEffectiveMixBlendMode() == CompositionOp::OP_OVER;
+}
+
+bool
+Layer::CanUseOpaqueSurface()
+{
+  // If the visible content in the layer is opaque, there is no need
+  // for an alpha channel.
+  if (GetContentFlags() & CONTENT_OPAQUE)
+    return true;
+  // Also, if this layer is the bottommost layer in a container which
+  // doesn't need an alpha channel, we can use an opaque surface for this
+  // layer too. Any transparent areas must be covered by something else
+  // in the container.
+  ContainerLayer* parent = GetParent();
+  return parent && parent->GetFirstChild() == this &&
+    parent->CanUseOpaqueSurface();
+}
+
+// NB: eventually these methods will be defined unconditionally, and
+// can be moved into Layers.h
+const Maybe<ParentLayerIntRect>&
+Layer::GetLocalClipRect()
+{
+  if (LayerComposite* shadow = AsLayerComposite()) {
+    return shadow->GetShadowClipRect();
+  }
+  return GetClipRect();
+}
+
+const LayerIntRegion&
+Layer::GetLocalVisibleRegion()
+{
+  if (LayerComposite* shadow = AsLayerComposite()) {
+    return shadow->GetShadowVisibleRegion();
+  }
+  return GetVisibleRegion();
+}
+
+Matrix4x4
+Layer::SnapTransformTranslation(const Matrix4x4& aTransform,
+                                Matrix* aResidualTransform)
+{
+  if (aResidualTransform) {
+    *aResidualTransform = Matrix();
+  }
+
+  if (!mManager->IsSnappingEffectiveTransforms()) {
+    return aTransform;
+  }
+
+  Matrix matrix2D;
+  if (aTransform.CanDraw2D(&matrix2D) &&
+      !matrix2D.HasNonTranslation() &&
+      matrix2D.HasNonIntegerTranslation()) {
+    auto snappedTranslation = IntPoint::Round(matrix2D.GetTranslation());
+    Matrix snappedMatrix = Matrix::Translation(snappedTranslation.x,
+                                               snappedTranslation.y);
+    Matrix4x4 result = Matrix4x4::From2D(snappedMatrix);
+    if (aResidualTransform) {
+      // set aResidualTransform so that aResidual * snappedMatrix == matrix2D.
+      // (I.e., appying snappedMatrix after aResidualTransform gives the
+      // ideal transform.)
+      *aResidualTransform =
+        Matrix::Translation(matrix2D._31 - snappedTranslation.x,
+                            matrix2D._32 - snappedTranslation.y);
+    }
+    return result;
+  }
+
+  return SnapTransformTranslation3D(aTransform, aResidualTransform);
+}
+
+Matrix4x4
+Layer::SnapTransformTranslation3D(const Matrix4x4& aTransform,
+                                  Matrix* aResidualTransform)
+{
+  if(aTransform.IsSingular() ||
+     aTransform.HasPerspectiveComponent() ||
+     aTransform.HasNonTranslation() ||
+     !aTransform.HasNonIntegerTranslation()) {
+    // For a singular transform, there is no reversed matrix, so we
+    // don't snap it.
+    // For a perspective transform, the content is transformed in
+    // non-linear, so we don't snap it too.
+    return aTransform;
+  }
+
+  // Snap for 3D Transforms
+
+  Point3D transformedOrigin = aTransform.TransformPoint(Point3D());
+
+  // Compute the transformed snap by rounding the values of
+  // transformed origin.
+  auto transformedSnapXY = IntPoint::Round(transformedOrigin.x, transformedOrigin.y);
+  Matrix4x4 inverse = aTransform;
+  inverse.Invert();
+  // see Matrix4x4::ProjectPoint()
+  Float transformedSnapZ =
+    inverse._33 == 0 ? 0 : (-(transformedSnapXY.x * inverse._13 +
+                              transformedSnapXY.y * inverse._23 +
+                              inverse._43) / inverse._33);
+  Point3D transformedSnap =
+    Point3D(transformedSnapXY.x, transformedSnapXY.y, transformedSnapZ);
+  if (transformedOrigin == transformedSnap) {
+    return aTransform;
+  }
+
+  // Compute the snap from the transformed snap.
+  Point3D snap = inverse.TransformPoint(transformedSnap);
+  if (snap.z > 0.001 || snap.z < -0.001) {
+    // Allow some level of accumulated computation error.
+    MOZ_ASSERT(inverse._33 == 0.0);
+    return aTransform;
+  }
+
+  // The difference between the origin and snap is the residual transform.
+  if (aResidualTransform) {
+    // The residual transform is to translate the snap to the origin
+    // of the content buffer.
+    *aResidualTransform = Matrix::Translation(-snap.x, -snap.y);
+  }
+
+  // Translate transformed origin to transformed snap since the
+  // residual transform would trnslate the snap to the origin.
+  Point3D transformedShift = transformedSnap - transformedOrigin;
+  Matrix4x4 result = aTransform;
+  result.PostTranslate(transformedShift.x,
+                       transformedShift.y,
+                       transformedShift.z);
+
+  // For non-2d transform, residual translation could be more than
+  // 0.5 pixels for every axis.
+
+  return result;
+}
+
+Matrix4x4
+Layer::SnapTransform(const Matrix4x4& aTransform,
+                     const gfxRect& aSnapRect,
+                     Matrix* aResidualTransform)
+{
+  if (aResidualTransform) {
+    *aResidualTransform = Matrix();
+  }
+
+  Matrix matrix2D;
+  Matrix4x4 result;
+  if (mManager->IsSnappingEffectiveTransforms() &&
+      aTransform.Is2D(&matrix2D) &&
+      gfxSize(1.0, 1.0) <= aSnapRect.Size() &&
+      matrix2D.PreservesAxisAlignedRectangles()) {
+    auto transformedTopLeft = IntPoint::Round(matrix2D.TransformPoint(ToPoint(aSnapRect.TopLeft())));
+    auto transformedTopRight = IntPoint::Round(matrix2D.TransformPoint(ToPoint(aSnapRect.TopRight())));
+    auto transformedBottomRight = IntPoint::Round(matrix2D.TransformPoint(ToPoint(aSnapRect.BottomRight())));
+
+    Matrix snappedMatrix = gfxUtils::TransformRectToRect(aSnapRect,
+      transformedTopLeft, transformedTopRight, transformedBottomRight);
+
+    result = Matrix4x4::From2D(snappedMatrix);
+    if (aResidualTransform && !snappedMatrix.IsSingular()) {
+      // set aResidualTransform so that aResidual * snappedMatrix == matrix2D.
+      // (i.e., appying snappedMatrix after aResidualTransform gives the
+      // ideal transform.
+      Matrix snappedMatrixInverse = snappedMatrix;
+      snappedMatrixInverse.Invert();
+      *aResidualTransform = matrix2D * snappedMatrixInverse;
+    }
+  } else {
+    result = aTransform;
+  }
+  return result;
+}
+
+static bool
+AncestorLayerMayChangeTransform(Layer* aLayer)
+{
+  for (Layer* l = aLayer; l; l = l->GetParent()) {
+    if (l->GetContentFlags() & Layer::CONTENT_MAY_CHANGE_TRANSFORM) {
+      return true;
+    }
+  }
+  return false;
+}
+
+bool
+Layer::MayResample()
+{
+  Matrix transform2d;
+  return !GetEffectiveTransform().Is2D(&transform2d) ||
+         ThebesMatrix(transform2d).HasNonIntegerTranslation() ||
+         AncestorLayerMayChangeTransform(this);
+}
+
+RenderTargetIntRect
+Layer::CalculateScissorRect(const RenderTargetIntRect& aCurrentScissorRect)
+{
+  ContainerLayer* container = GetParent();
+  ContainerLayer* containerChild = nullptr;
+  NS_ASSERTION(GetParent(), "This can't be called on the root!");
+
+  // Find the layer creating the 3D context.
+  while (container->Extend3DContext() &&
+         !container->UseIntermediateSurface()) {
+    containerChild = container;
+    container = container->GetParent();
+    MOZ_ASSERT(container);
+  }
+
+  // Find the nearest layer with a clip, or this layer.
+  // ContainerState::SetupScrollingMetadata() may install a clip on
+  // the layer.
+  Layer *clipLayer =
+    containerChild && containerChild->GetLocalClipRect() ?
+    containerChild : this;
+
+  // Establish initial clip rect: it's either the one passed in, or
+  // if the parent has an intermediate surface, it's the extents of that surface.
+  RenderTargetIntRect currentClip;
+  if (container->UseIntermediateSurface()) {
+    currentClip.SizeTo(container->GetIntermediateSurfaceRect().Size());
+  } else {
+    currentClip = aCurrentScissorRect;
+  }
+
+  if (!clipLayer->GetLocalClipRect()) {
+    return currentClip;
+  }
+
+  if (GetLocalVisibleRegion().IsEmpty() &&
+      !(AsLayerComposite() && AsLayerComposite()->NeedToDrawCheckerboarding())) {
+    // When our visible region is empty, our parent may not have created the
+    // intermediate surface that we would require for correct clipping; however,
+    // this does not matter since we are invisible.
+    // Make sure we still compute a clip rect if we want to draw checkboarding
+    // for this layer, since we want to do this even if the layer is invisible.
+    return RenderTargetIntRect(currentClip.TopLeft(), RenderTargetIntSize(0, 0));
+  }
+
+  const RenderTargetIntRect clipRect =
+    ViewAs<RenderTargetPixel>(*clipLayer->GetLocalClipRect(),
+                              PixelCastJustification::RenderTargetIsParentLayerForRoot);
+  if (clipRect.IsEmpty()) {
+    // We might have a non-translation transform in the container so we can't
+    // use the code path below.
+    return RenderTargetIntRect(currentClip.TopLeft(), RenderTargetIntSize(0, 0));
+  }
+
+  RenderTargetIntRect scissor = clipRect;
+  if (!container->UseIntermediateSurface()) {
+    gfx::Matrix matrix;
+    DebugOnly<bool> is2D = container->GetEffectiveTransform().Is2D(&matrix);
+    // See DefaultComputeEffectiveTransforms below
+    NS_ASSERTION(is2D && matrix.PreservesAxisAlignedRectangles(),
+                 "Non preserves axis aligned transform with clipped child should have forced intermediate surface");
+    gfx::Rect r(scissor.x, scissor.y, scissor.width, scissor.height);
+    gfxRect trScissor = gfx::ThebesRect(matrix.TransformBounds(r));
+    trScissor.Round();
+    IntRect tmp;
+    if (!gfxUtils::GfxRectToIntRect(trScissor, &tmp)) {
+      return RenderTargetIntRect(currentClip.TopLeft(), RenderTargetIntSize(0, 0));
+    }
+    scissor = ViewAs<RenderTargetPixel>(tmp);
+
+    // Find the nearest ancestor with an intermediate surface
+    do {
+      container = container->GetParent();
+    } while (container && !container->UseIntermediateSurface());
+  }
+
+  if (container) {
+    scissor.MoveBy(-container->GetIntermediateSurfaceRect().TopLeft());
+  }
+  return currentClip.Intersect(scissor);
+}
+
+Maybe<ParentLayerIntRect>
+Layer::GetScrolledClipRect() const
+{
+  return mScrolledClip ? Some(mScrolledClip->GetClipRect()) : Nothing();
+}
+
+const ScrollMetadata&
+Layer::GetScrollMetadata(uint32_t aIndex) const
+{
+  MOZ_ASSERT(aIndex < GetScrollMetadataCount());
+  return mScrollMetadata[aIndex];
+}
+
+const FrameMetrics&
+Layer::GetFrameMetrics(uint32_t aIndex) const
+{
+  return GetScrollMetadata(aIndex).GetMetrics();
+}
+
+bool
+Layer::HasScrollableFrameMetrics() const
+{
+  for (uint32_t i = 0; i < GetScrollMetadataCount(); i++) {
+    if (GetFrameMetrics(i).IsScrollable()) {
+      return true;
+    }
+  }
+  return false;
+}
+
+bool
+Layer::IsScrollInfoLayer() const
+{
+  // A scrollable container layer with no children
+  return AsContainerLayer()
+      && HasScrollableFrameMetrics()
+      && !GetFirstChild();
+}
+
+Matrix4x4
+Layer::GetTransform() const
+{
+  Matrix4x4 transform = mTransform;
+  transform.PostScale(GetPostXScale(), GetPostYScale(), 1.0f);
+  if (const ContainerLayer* c = AsContainerLayer()) {
+    transform.PreScale(c->GetPreXScale(), c->GetPreYScale(), 1.0f);
+  }
+  return transform;
+}
+
+const CSSTransformMatrix
+Layer::GetTransformTyped() const
+{
+  return ViewAs<CSSTransformMatrix>(GetTransform());
+}
+
+Matrix4x4
+Layer::GetLocalTransform()
+{
+  if (LayerComposite* shadow = AsLayerComposite())
+    return shadow->GetShadowTransform();
+  else
+    return GetTransform();
+}
+
+const LayerToParentLayerMatrix4x4
+Layer::GetLocalTransformTyped()
+{
+  return ViewAs<LayerToParentLayerMatrix4x4>(GetLocalTransform());
+}
+
+bool
+Layer::HasTransformAnimation() const
+{
+  for (uint32_t i = 0; i < mAnimations.Length(); i++) {
+    if (mAnimations[i].property() == eCSSProperty_transform) {
+      return true;
+    }
+  }
+  return false;
+}
+
+void
+Layer::ApplyPendingUpdatesForThisTransaction()
+{
+  if (mPendingTransform && *mPendingTransform != mTransform) {
+    MOZ_LAYERS_LOG_IF_SHADOWABLE(this, ("Layer::Mutated(%p) PendingUpdatesForThisTransaction", this));
+    mTransform = *mPendingTransform;
+    Mutated();
+  }
+  mPendingTransform = nullptr;
+
+  if (mPendingAnimations) {
+    MOZ_LAYERS_LOG_IF_SHADOWABLE(this, ("Layer::Mutated(%p) PendingUpdatesForThisTransaction", this));
+    mPendingAnimations->SwapElements(mAnimations);
+    mPendingAnimations = nullptr;
+    Mutated();
+  }
+
+  for (size_t i = 0; i < mScrollMetadata.Length(); i++) {
+    FrameMetrics& fm = mScrollMetadata[i].GetMetrics();
+    Maybe<ScrollUpdateInfo> update = Manager()->GetPendingScrollInfoUpdate(fm.GetScrollId());
+    if (update) {
+      fm.UpdatePendingScrollInfo(update.value());
+      Mutated();
+    }
+  }
+}
+
+float
+Layer::GetLocalOpacity()
+{
+  float opacity = mOpacity;
+  if (LayerComposite* shadow = AsLayerComposite())
+    opacity = shadow->GetShadowOpacity();
+  return std::min(std::max(opacity, 0.0f), 1.0f);
+}
+
+float
+Layer::GetEffectiveOpacity()
+{
+  float opacity = GetLocalOpacity();
+  for (ContainerLayer* c = GetParent(); c && !c->UseIntermediateSurface();
+       c = c->GetParent()) {
+    opacity *= c->GetLocalOpacity();
+  }
+  return opacity;
+}
+
+CompositionOp
+Layer::GetEffectiveMixBlendMode()
+{
+  if(mMixBlendMode != CompositionOp::OP_OVER)
+    return mMixBlendMode;
+  for (ContainerLayer* c = GetParent(); c && !c->UseIntermediateSurface();
+    c = c->GetParent()) {
+    if(c->mMixBlendMode != CompositionOp::OP_OVER)
+      return c->mMixBlendMode;
+  }
+
+  return mMixBlendMode;
+}
+
+void
+Layer::ComputeEffectiveTransformForMaskLayers(const gfx::Matrix4x4& aTransformToSurface)
+{
+  if (GetMaskLayer()) {
+    ComputeEffectiveTransformForMaskLayer(GetMaskLayer(), aTransformToSurface);
+  }
+  for (size_t i = 0; i < GetAncestorMaskLayerCount(); i++) {
+    Layer* maskLayer = GetAncestorMaskLayerAt(i);
+    ComputeEffectiveTransformForMaskLayer(maskLayer, aTransformToSurface);
+  }
+}
+
+/* static */ void
+Layer::ComputeEffectiveTransformForMaskLayer(Layer* aMaskLayer, const gfx::Matrix4x4& aTransformToSurface)
+{
+  aMaskLayer->mEffectiveTransform = aTransformToSurface;
+
+#ifdef DEBUG
+  bool maskIs2D = aMaskLayer->GetTransform().CanDraw2D();
+  NS_ASSERTION(maskIs2D, "How did we end up with a 3D transform here?!");
+#endif
+  // The mask layer can have an async transform applied to it in some
+  // situations, so be sure to use its GetLocalTransform() rather than
+  // its GetTransform().
+  aMaskLayer->mEffectiveTransform = aMaskLayer->GetLocalTransform() *
+    aMaskLayer->mEffectiveTransform;
+}
+
+RenderTargetRect
+Layer::TransformRectToRenderTarget(const LayerIntRect& aRect)
+{
+  LayerRect rect(aRect);
+  RenderTargetRect quad = RenderTargetRect::FromUnknownRect(
+    GetEffectiveTransform().TransformBounds(rect.ToUnknownRect()));
+  return quad;
+}
+
+bool
+Layer::GetVisibleRegionRelativeToRootLayer(nsIntRegion& aResult,
+                                           IntPoint* aLayerOffset)
+{
+  MOZ_ASSERT(aLayerOffset, "invalid offset pointer");
+
+  if (!GetParent()) {
+    return false;
+  }
+
+  IntPoint offset;
+  aResult = GetLocalVisibleRegion().ToUnknownRegion();
+  for (Layer* layer = this; layer; layer = layer->GetParent()) {
+    gfx::Matrix matrix;
+    if (!layer->GetLocalTransform().Is2D(&matrix) ||
+        !matrix.IsTranslation()) {
+      return false;
+    }
+
+    // The offset of |layer| to its parent.
+    auto currentLayerOffset = IntPoint::Round(matrix.GetTranslation());
+
+    // Translate the accumulated visible region of |this| by the offset of
+    // |layer|.
+    aResult.MoveBy(currentLayerOffset.x, currentLayerOffset.y);
+
+    // If the parent layer clips its lower layers, clip the visible region
+    // we're accumulating.
+    if (layer->GetLocalClipRect()) {
+      aResult.AndWith(layer->GetLocalClipRect()->ToUnknownRect());
+    }
+
+    // Now we need to walk across the list of siblings for this parent layer,
+    // checking to see if any of these layer trees obscure |this|. If so,
+    // remove these areas from the visible region as well. This will pick up
+    // chrome overlays like a tab modal prompt.
+    Layer* sibling;
+    for (sibling = layer->GetNextSibling(); sibling;
+         sibling = sibling->GetNextSibling()) {
+      gfx::Matrix siblingMatrix;
+      if (!sibling->GetLocalTransform().Is2D(&siblingMatrix) ||
+          !siblingMatrix.IsTranslation()) {
+        continue;
+      }
+
+      // Retreive the translation from sibling to |layer|. The accumulated
+      // visible region is currently oriented with |layer|.
+      auto siblingOffset = IntPoint::Round(siblingMatrix.GetTranslation());
+      nsIntRegion siblingVisibleRegion(sibling->GetLocalVisibleRegion().ToUnknownRegion());
+      // Translate the siblings region to |layer|'s origin.
+      siblingVisibleRegion.MoveBy(-siblingOffset.x, -siblingOffset.y);
+      // Apply the sibling's clip.
+      // Layer clip rects are not affected by the layer's transform.
+      Maybe<ParentLayerIntRect> clipRect = sibling->GetLocalClipRect();
+      if (clipRect) {
+        siblingVisibleRegion.AndWith(clipRect->ToUnknownRect());
+      }
+      // Subtract the sibling visible region from the visible region of |this|.
+      aResult.SubOut(siblingVisibleRegion);
+    }
+
+    // Keep track of the total offset for aLayerOffset.  We use this in plugin
+    // positioning code.
+    offset += currentLayerOffset;
+  }
+
+  *aLayerOffset = IntPoint(offset.x, offset.y);
+  return true;
+}
+
+Maybe<ParentLayerIntRect>
+Layer::GetCombinedClipRect() const
+{
+  Maybe<ParentLayerIntRect> clip = GetClipRect();
+
+  clip = IntersectMaybeRects(clip, GetScrolledClipRect());
+
+  for (size_t i = 0; i < mScrollMetadata.Length(); i++) {
+    clip = IntersectMaybeRects(clip, mScrollMetadata[i].GetClipRect());
+  }
+
+  return clip;
+}
+
+ContainerLayer::ContainerLayer(LayerManager* aManager, void* aImplData)
+  : Layer(aManager, aImplData),
+    mFirstChild(nullptr),
+    mLastChild(nullptr),
+    mPreXScale(1.0f),
+    mPreYScale(1.0f),
+    mInheritedXScale(1.0f),
+    mInheritedYScale(1.0f),
+    mPresShellResolution(1.0f),
+    mScaleToResolution(false),
+    mUseIntermediateSurface(false),
+    mSupportsComponentAlphaChildren(false),
+    mMayHaveReadbackChild(false),
+    mChildrenChanged(false),
+    mEventRegionsOverride(EventRegionsOverride::NoOverride)
+{
+  MOZ_COUNT_CTOR(ContainerLayer);
+  mContentFlags = 0; // Clear NO_TEXT, NO_TEXT_OVER_TRANSPARENT
+}
+
+ContainerLayer::~ContainerLayer()
+{
+  MOZ_COUNT_DTOR(ContainerLayer);
+}
+
+bool
+ContainerLayer::InsertAfter(Layer* aChild, Layer* aAfter)
+{
+  if(aChild->Manager() != Manager()) {
+    NS_ERROR("Child has wrong manager");
+    return false;
+  }
+  if(aChild->GetParent()) {
+    NS_ERROR("aChild already in the tree");
+    return false;
+  }
+  if (aChild->GetNextSibling() || aChild->GetPrevSibling()) {
+    NS_ERROR("aChild already has siblings?");
+    return false;
+  }
+  if (aAfter && (aAfter->Manager() != Manager() ||
+                 aAfter->GetParent() != this))
+  {
+    NS_ERROR("aAfter is not our child");
+    return false;
+  }
+
+  aChild->SetParent(this);
+  if (aAfter == mLastChild) {
+    mLastChild = aChild;
+  }
+  if (!aAfter) {
+    aChild->SetNextSibling(mFirstChild);
+    if (mFirstChild) {
+      mFirstChild->SetPrevSibling(aChild);
+    }
+    mFirstChild = aChild;
+    NS_ADDREF(aChild);
+    DidInsertChild(aChild);
+    return true;
+  }
+
+  Layer* next = aAfter->GetNextSibling();
+  aChild->SetNextSibling(next);
+  aChild->SetPrevSibling(aAfter);
+  if (next) {
+    next->SetPrevSibling(aChild);
+  }
+  aAfter->SetNextSibling(aChild);
+  NS_ADDREF(aChild);
+  DidInsertChild(aChild);
+  return true;
+}
+
+bool
+ContainerLayer::RemoveChild(Layer *aChild)
+{
+  if (aChild->Manager() != Manager()) {
+    NS_ERROR("Child has wrong manager");
+    return false;
+  }
+  if (aChild->GetParent() != this) {
+    NS_ERROR("aChild not our child");
+    return false;
+  }
+
+  Layer* prev = aChild->GetPrevSibling();
+  Layer* next = aChild->GetNextSibling();
+  if (prev) {
+    prev->SetNextSibling(next);
+  } else {
+    this->mFirstChild = next;
+  }
+  if (next) {
+    next->SetPrevSibling(prev);
+  } else {
+    this->mLastChild = prev;
+  }
+
+  aChild->SetNextSibling(nullptr);
+  aChild->SetPrevSibling(nullptr);
+  aChild->SetParent(nullptr);
+
+  this->DidRemoveChild(aChild);
+  NS_RELEASE(aChild);
+  return true;
+}
+
+
+bool
+ContainerLayer::RepositionChild(Layer* aChild, Layer* aAfter)
+{
+  if (aChild->Manager() != Manager()) {
+    NS_ERROR("Child has wrong manager");
+    return false;
+  }
+  if (aChild->GetParent() != this) {
+    NS_ERROR("aChild not our child");
+    return false;
+  }
+  if (aAfter && (aAfter->Manager() != Manager() ||
+                 aAfter->GetParent() != this))
+  {
+    NS_ERROR("aAfter is not our child");
+    return false;
+  }
+  if (aChild == aAfter) {
+    NS_ERROR("aChild cannot be the same as aAfter");
+    return false;
+  }
+
+  Layer* prev = aChild->GetPrevSibling();
+  Layer* next = aChild->GetNextSibling();
+  if (prev == aAfter) {
+    // aChild is already in the correct position, nothing to do.
+    return true;
+  }
+  if (prev) {
+    prev->SetNextSibling(next);
+  } else {
+    mFirstChild = next;
+  }
+  if (next) {
+    next->SetPrevSibling(prev);
+  } else {
+    mLastChild = prev;
+  }
+  if (!aAfter) {
+    aChild->SetPrevSibling(nullptr);
+    aChild->SetNextSibling(mFirstChild);
+    if (mFirstChild) {
+      mFirstChild->SetPrevSibling(aChild);
+    }
+    mFirstChild = aChild;
+    return true;
+  }
+
+  Layer* afterNext = aAfter->GetNextSibling();
+  if (afterNext) {
+    afterNext->SetPrevSibling(aChild);
+  } else {
+    mLastChild = aChild;
+  }
+  aAfter->SetNextSibling(aChild);
+  aChild->SetPrevSibling(aAfter);
+  aChild->SetNextSibling(afterNext);
+  return true;
+}
+
+void
+ContainerLayer::FillSpecificAttributes(SpecificLayerAttributes& aAttrs)
+{
+  aAttrs = ContainerLayerAttributes(mPreXScale, mPreYScale,
+                                    mInheritedXScale, mInheritedYScale,
+                                    mPresShellResolution, mScaleToResolution,
+                                    mEventRegionsOverride);
+}
+
+bool
+ContainerLayer::Creates3DContextWithExtendingChildren()
+{
+  if (Extend3DContext()) {
+    return false;
+  }
+  for (Layer* child = GetFirstChild();
+       child;
+       child = child->GetNextSibling()) {
+      if (child->Extend3DContext()) {
+        return true;
+      }
+  }
+  return false;
+}
+
+bool
+ContainerLayer::HasMultipleChildren()
+{
+  uint32_t count = 0;
+  for (Layer* child = GetFirstChild(); child; child = child->GetNextSibling()) {
+    const Maybe<ParentLayerIntRect>& clipRect = child->GetLocalClipRect();
+    if (clipRect && clipRect->IsEmpty())
+      continue;
+    if (child->GetLocalVisibleRegion().IsEmpty())
+      continue;
+    ++count;
+    if (count > 1)
+      return true;
+  }
+
+  return false;
+}
+
+/**
+ * Collect all leaf descendants of the current 3D context.
+ */
+void
+ContainerLayer::Collect3DContextLeaves(nsTArray<Layer*>& aToSort)
+{
+  ForEachNode<ForwardIterator>(
+      (Layer*) this,
+      [this, &aToSort](Layer* layer)
+      {
+        ContainerLayer* container = layer->AsContainerLayer();
+        if (layer == this || (container && container->Extend3DContext() &&
+            !container->UseIntermediateSurface())) {
+          return TraversalFlag::Continue;
+        }
+        else {
+          aToSort.AppendElement(layer);
+          return TraversalFlag::Skip;
+        }
+      }
+  );
+}
+
+void
+ContainerLayer::SortChildrenBy3DZOrder(nsTArray<Layer*>& aArray)
+{
+  AutoTArray<Layer*, 10> toSort;
+
+  for (Layer* l = GetFirstChild(); l; l = l->GetNextSibling()) {
+    ContainerLayer* container = l->AsContainerLayer();
+    if (container && container->Extend3DContext() &&
+        !container->UseIntermediateSurface()) {
+      container->Collect3DContextLeaves(toSort);
+    } else {
+      if (toSort.Length() > 0) {
+        SortLayersBy3DZOrder(toSort);
+        aArray.AppendElements(Move(toSort));
+        // XXX The move analysis gets confused here, because toSort gets moved
+        // here, and then gets used again outside of the loop. To clarify that
+        // we realize that the array is going to be empty to the move checker,
+        // we clear it again here. (This method renews toSort for the move
+        // analysis)
+        toSort.ClearAndRetainStorage();
+      }
+      aArray.AppendElement(l);
+    }
+  }
+  if (toSort.Length() > 0) {
+    SortLayersBy3DZOrder(toSort);
+    aArray.AppendElements(Move(toSort));
+  }
+}
+
+void
+ContainerLayer::DefaultComputeEffectiveTransforms(const Matrix4x4& aTransformToSurface)
+{
+  Matrix residual;
+  Matrix4x4 idealTransform = GetLocalTransform() * aTransformToSurface;
+
+  // Keep 3D transforms for leaves to keep z-order sorting correct.
+  if (!Extend3DContext() && !Is3DContextLeaf()) {
+    idealTransform.ProjectTo2D();
+  }
+
+  bool useIntermediateSurface;
+  if (HasMaskLayers() ||
+      GetForceIsolatedGroup()) {
+    useIntermediateSurface = true;
+#ifdef MOZ_DUMP_PAINTING
+  } else if (gfxEnv::DumpPaintIntermediate() && !Extend3DContext()) {
+    useIntermediateSurface = true;
+#endif
+  } else {
+    /* Don't use an intermediate surface for opacity when it's within a 3d
+     * context, since we'd rather keep the 3d effects. This matches the
+     * WebKit/blink behaviour, but is changing in the latest spec.
+     */
+    float opacity = GetEffectiveOpacity();
+    CompositionOp blendMode = GetEffectiveMixBlendMode();
+    if ((HasMultipleChildren() || Creates3DContextWithExtendingChildren()) &&
+        ((opacity != 1.0f && !Extend3DContext()) ||
+         (blendMode != CompositionOp::OP_OVER))) {
+      useIntermediateSurface = true;
+    } else if (!idealTransform.Is2D() && Creates3DContextWithExtendingChildren()) {
+      useIntermediateSurface = true;
+    } else {
+      useIntermediateSurface = false;
+      gfx::Matrix contTransform;
+      bool checkClipRect = false;
+      bool checkMaskLayers = false;
+
+      if (!idealTransform.Is2D(&contTransform)) {
+        // In 3D case, always check if we should use IntermediateSurface.
+        checkClipRect = true;
+        checkMaskLayers = true;
+      } else {
+#ifdef MOZ_GFX_OPTIMIZE_MOBILE
+        if (!contTransform.PreservesAxisAlignedRectangles()) {
+#else
+        if (gfx::ThebesMatrix(contTransform).HasNonIntegerTranslation()) {
+#endif
+          checkClipRect = true;
+        }
+        /* In 2D case, only translation and/or positive scaling can be done w/o using IntermediateSurface.
+         * Otherwise, when rotation or flip happen, we should check whether to use IntermediateSurface.
+         */
+        if (contTransform.HasNonAxisAlignedTransform() || contTransform.HasNegativeScaling()) {
+          checkMaskLayers = true;
+        }
+      }
+
+      if (checkClipRect || checkMaskLayers) {
+        for (Layer* child = GetFirstChild(); child; child = child->GetNextSibling()) {
+          const Maybe<ParentLayerIntRect>& clipRect = child->GetLocalClipRect();
+          /* We can't (easily) forward our transform to children with a non-empty clip
+           * rect since it would need to be adjusted for the transform. See
+           * the calculations performed by CalculateScissorRect above.
+           * Nor for a child with a mask layer.
+           */
+          if (checkClipRect && (clipRect && !clipRect->IsEmpty() && !child->GetLocalVisibleRegion().IsEmpty())) {
+            useIntermediateSurface = true;
+            break;
+          }
+          if (checkMaskLayers && child->HasMaskLayers()) {
+            useIntermediateSurface = true;
+            break;
+          }
+        }
+      }
+    }
+  }
+
+  NS_ASSERTION(!Extend3DContext() || !useIntermediateSurface, "Can't have an intermediate surface with preserve-3d!");
+
+  if (useIntermediateSurface) {
+    mEffectiveTransform = SnapTransformTranslation(idealTransform, &residual);
+  } else {
+    mEffectiveTransform = idealTransform;
+  }
+
+  // For layers extending 3d context, its ideal transform should be
+  // applied on children.
+  if (!Extend3DContext()) {
+    // Without this projection, non-container children would get a 3D
+    // transform while 2D is expected.
+    idealTransform.ProjectTo2D();
+  }
+  mUseIntermediateSurface = useIntermediateSurface && !GetLocalVisibleRegion().IsEmpty();
+  if (useIntermediateSurface) {
+    ComputeEffectiveTransformsForChildren(Matrix4x4::From2D(residual));
+  } else {
+    ComputeEffectiveTransformsForChildren(idealTransform);
+  }
+
+  ComputeEffectiveTransformForMaskLayers(aTransformToSurface);
+}
+
+void
+ContainerLayer::DefaultComputeSupportsComponentAlphaChildren(bool* aNeedsSurfaceCopy)
+{
+  if (!(GetContentFlags() & Layer::CONTENT_COMPONENT_ALPHA_DESCENDANT) ||
+      !Manager()->AreComponentAlphaLayersEnabled()) {
+    mSupportsComponentAlphaChildren = false;
+    if (aNeedsSurfaceCopy) {
+      *aNeedsSurfaceCopy = false;
+    }
+    return;
+  }
+
+  mSupportsComponentAlphaChildren = false;
+  bool needsSurfaceCopy = false;
+  CompositionOp blendMode = GetEffectiveMixBlendMode();
+  if (UseIntermediateSurface()) {
+    if (GetLocalVisibleRegion().GetNumRects() == 1 &&
+        (GetContentFlags() & Layer::CONTENT_OPAQUE))
+    {
+      mSupportsComponentAlphaChildren = true;
+    } else {
+      gfx::Matrix transform;
+      if (HasOpaqueAncestorLayer(this) &&
+          GetEffectiveTransform().Is2D(&transform) &&
+          !gfx::ThebesMatrix(transform).HasNonIntegerTranslation() &&
+          blendMode == gfx::CompositionOp::OP_OVER) {
+        mSupportsComponentAlphaChildren = true;
+        needsSurfaceCopy = true;
+      }
+    }
+  } else if (blendMode == gfx::CompositionOp::OP_OVER) {
+    mSupportsComponentAlphaChildren =
+      (GetContentFlags() & Layer::CONTENT_OPAQUE) ||
+      (GetParent() && GetParent()->SupportsComponentAlphaChildren());
+  }
+
+  if (aNeedsSurfaceCopy) {
+    *aNeedsSurfaceCopy = mSupportsComponentAlphaChildren && needsSurfaceCopy;
+  }
+}
+
+void
+ContainerLayer::ComputeEffectiveTransformsForChildren(const Matrix4x4& aTransformToSurface)
+{
+  for (Layer* l = mFirstChild; l; l = l->GetNextSibling()) {
+    l->ComputeEffectiveTransforms(aTransformToSurface);
+  }
+}
+
+/* static */ bool
+ContainerLayer::HasOpaqueAncestorLayer(Layer* aLayer)
+{
+  for (Layer* l = aLayer->GetParent(); l; l = l->GetParent()) {
+    if (l->GetContentFlags() & Layer::CONTENT_OPAQUE)
+      return true;
+  }
+  return false;
+}
+
+void
+ContainerLayer::DidRemoveChild(Layer* aLayer)
+{
+  PaintedLayer* tl = aLayer->AsPaintedLayer();
+  if (tl && tl->UsedForReadback()) {
+    for (Layer* l = mFirstChild; l; l = l->GetNextSibling()) {
+      if (l->GetType() == TYPE_READBACK) {
+        static_cast<ReadbackLayer*>(l)->NotifyPaintedLayerRemoved(tl);
+      }
+    }
+  }
+  if (aLayer->GetType() == TYPE_READBACK) {
+    static_cast<ReadbackLayer*>(aLayer)->NotifyRemoved();
+  }
+}
+
+void
+ContainerLayer::DidInsertChild(Layer* aLayer)
+{
+  if (aLayer->GetType() == TYPE_READBACK) {
+    mMayHaveReadbackChild = true;
+  }
+}
+
+void
+RefLayer::FillSpecificAttributes(SpecificLayerAttributes& aAttrs)
+{
+  aAttrs = RefLayerAttributes(GetReferentId(), mEventRegionsOverride);
+}
+
+/**
+ * StartFrameTimeRecording, together with StopFrameTimeRecording
+ * enable recording of frame intervals.
+ *
+ * To allow concurrent consumers, a cyclic array is used which serves all
+ * consumers, practically stateless with regard to consumers.
+ *
+ * To save resources, the buffer is allocated on first call to StartFrameTimeRecording
+ * and recording is paused if no consumer which called StartFrameTimeRecording is able
+ * to get valid results (because the cyclic buffer was overwritten since that call).
+ *
+ * To determine availability of the data upon StopFrameTimeRecording:
+ * - mRecording.mNextIndex increases on each PostPresent, and never resets.
+ * - Cyclic buffer position is realized as mNextIndex % bufferSize.
+ * - StartFrameTimeRecording returns mNextIndex. When StopFrameTimeRecording is called,
+ *   the required start index is passed as an arg, and we're able to calculate the required
+ *   length. If this length is bigger than bufferSize, it means data was overwritten.
+ *   otherwise, we can return the entire sequence.
+ * - To determine if we need to pause, mLatestStartIndex is updated to mNextIndex
+ *   on each call to StartFrameTimeRecording. If this index gets overwritten,
+ *   it means that all earlier start indices obtained via StartFrameTimeRecording
+ *   were also overwritten, hence, no point in recording, so pause.
+ * - mCurrentRunStartIndex indicates the oldest index of the recording after which
+ *   the recording was not paused. If StopFrameTimeRecording is invoked with a start index
+ *   older than this, it means that some frames were not recorded, so data is invalid.
+ */
+uint32_t
+LayerManager::StartFrameTimeRecording(int32_t aBufferSize)
+{
+  if (mRecording.mIsPaused) {
+    mRecording.mIsPaused = false;
+
+    if (!mRecording.mIntervals.Length()) { // Initialize recording buffers
+      mRecording.mIntervals.SetLength(aBufferSize);
+    }
+
+    // After being paused, recent values got invalid. Update them to now.
+    mRecording.mLastFrameTime = TimeStamp::Now();
+
+    // Any recording which started before this is invalid, since we were paused.
+    mRecording.mCurrentRunStartIndex = mRecording.mNextIndex;
+  }
+
+  // If we'll overwrite this index, there are no more consumers with aStartIndex
+  // for which we're able to provide the full recording, so no point in keep recording.
+  mRecording.mLatestStartIndex = mRecording.mNextIndex;
+  return mRecording.mNextIndex;
+}
+
+void
+LayerManager::RecordFrame()
+{
+  if (!mRecording.mIsPaused) {
+    TimeStamp now = TimeStamp::Now();
+    uint32_t i = mRecording.mNextIndex % mRecording.mIntervals.Length();
+    mRecording.mIntervals[i] = static_cast<float>((now - mRecording.mLastFrameTime)
+                                                  .ToMilliseconds());
+    mRecording.mNextIndex++;
+    mRecording.mLastFrameTime = now;
+
+    if (mRecording.mNextIndex > (mRecording.mLatestStartIndex + mRecording.mIntervals.Length())) {
+      // We've just overwritten the most recent recording start -> pause.
+      mRecording.mIsPaused = true;
+    }
+  }
+}
+
+void
+LayerManager::PostPresent()
+{
+  if (!mTabSwitchStart.IsNull()) {
+    Telemetry::Accumulate(Telemetry::FX_TAB_SWITCH_TOTAL_MS,
+                          uint32_t((TimeStamp::Now() - mTabSwitchStart).ToMilliseconds()));
+    mTabSwitchStart = TimeStamp();
+  }
+}
+
+void
+LayerManager::StopFrameTimeRecording(uint32_t         aStartIndex,
+                                     nsTArray<float>& aFrameIntervals)
+{
+  uint32_t bufferSize = mRecording.mIntervals.Length();
+  uint32_t length = mRecording.mNextIndex - aStartIndex;
+  if (mRecording.mIsPaused || length > bufferSize || aStartIndex < mRecording.mCurrentRunStartIndex) {
+    // aStartIndex is too old. Also if aStartIndex was issued before mRecordingNextIndex overflowed (uint32_t)
+    //   and stopped after the overflow (would happen once every 828 days of constant 60fps).
+    length = 0;
+  }
+
+  if (!length) {
+    aFrameIntervals.Clear();
+    return; // empty recording, return empty arrays.
+  }
+  // Set length in advance to avoid possibly repeated reallocations
+  aFrameIntervals.SetLength(length);
+
+  uint32_t cyclicPos = aStartIndex % bufferSize;
+  for (uint32_t i = 0; i < length; i++, cyclicPos++) {
+    if (cyclicPos == bufferSize) {
+      cyclicPos = 0;
+    }
+    aFrameIntervals[i] = mRecording.mIntervals[cyclicPos];
+  }
+}
+
+void
+LayerManager::BeginTabSwitch()
+{
+  mTabSwitchStart = TimeStamp::Now();
+}
+
+static void PrintInfo(std::stringstream& aStream, LayerComposite* aLayerComposite);
+
+#ifdef MOZ_DUMP_PAINTING
+template <typename T>
+void WriteSnapshotToDumpFile_internal(T* aObj, DataSourceSurface* aSurf)
+{
+  nsCString string(aObj->Name());
+  string.Append('-');
+  string.AppendInt((uint64_t)aObj);
+  if (gfxUtils::sDumpPaintFile != stderr) {
+    fprintf_stderr(gfxUtils::sDumpPaintFile, "array[\"%s\"]=\"", string.BeginReading());
+  }
+  gfxUtils::DumpAsDataURI(aSurf, gfxUtils::sDumpPaintFile);
+  if (gfxUtils::sDumpPaintFile != stderr) {
+    fprintf_stderr(gfxUtils::sDumpPaintFile, "\";");
+  }
+}
+
+void WriteSnapshotToDumpFile(Layer* aLayer, DataSourceSurface* aSurf)
+{
+  WriteSnapshotToDumpFile_internal(aLayer, aSurf);
+}
+
+void WriteSnapshotToDumpFile(LayerManager* aManager, DataSourceSurface* aSurf)
+{
+  WriteSnapshotToDumpFile_internal(aManager, aSurf);
+}
+
+void WriteSnapshotToDumpFile(Compositor* aCompositor, DrawTarget* aTarget)
+{
+  RefPtr<SourceSurface> surf = aTarget->Snapshot();
+  RefPtr<DataSourceSurface> dSurf = surf->GetDataSurface();
+  WriteSnapshotToDumpFile_internal(aCompositor, dSurf);
+}
+#endif
+
+void
+Layer::Dump(std::stringstream& aStream, const char* aPrefix,
+            bool aDumpHtml, bool aSorted)
+{
+#ifdef MOZ_DUMP_PAINTING
+  bool dumpCompositorTexture = gfxEnv::DumpCompositorTextures() && AsLayerComposite() &&
+                               AsLayerComposite()->GetCompositableHost();
+  bool dumpClientTexture = gfxEnv::DumpPaint() && AsShadowableLayer() &&
+                           AsShadowableLayer()->GetCompositableClient();
+  nsCString layerId(Name());
+  layerId.Append('-');
+  layerId.AppendInt((uint64_t)this);
+#endif
+  if (aDumpHtml) {
+    aStream << nsPrintfCString("<li><a id=\"%p\" ", this).get();
+#ifdef MOZ_DUMP_PAINTING
+    if (dumpCompositorTexture || dumpClientTexture) {
+      aStream << nsPrintfCString("href=\"javascript:ViewImage('%s')\"", layerId.BeginReading()).get();
+    }
+#endif
+    aStream << ">";
+  }
+  DumpSelf(aStream, aPrefix);
+
+#ifdef MOZ_DUMP_PAINTING
+  if (dumpCompositorTexture) {
+    AsLayerComposite()->GetCompositableHost()->Dump(aStream, aPrefix, aDumpHtml);
+  } else if (dumpClientTexture) {
+    if (aDumpHtml) {
+      aStream << nsPrintfCString("<script>array[\"%s\"]=\"", layerId.BeginReading()).get();
+    }
+    AsShadowableLayer()->GetCompositableClient()->Dump(aStream, aPrefix,
+        aDumpHtml, TextureDumpMode::DoNotCompress);
+    if (aDumpHtml) {
+      aStream << "\";</script>";
+    }
+  }
+#endif
+
+  if (aDumpHtml) {
+    aStream << "</a>";
+#ifdef MOZ_DUMP_PAINTING
+    if (dumpClientTexture) {
+      aStream << nsPrintfCString("<br><img id=\"%s\">\n", layerId.BeginReading()).get();
+    }
+#endif
+  }
+
+  if (Layer* mask = GetMaskLayer()) {
+    aStream << nsPrintfCString("%s  Mask layer:\n", aPrefix).get();
+    nsAutoCString pfx(aPrefix);
+    pfx += "    ";
+    mask->Dump(aStream, pfx.get(), aDumpHtml);
+  }
+
+  for (size_t i = 0; i < GetAncestorMaskLayerCount(); i++) {
+    aStream << nsPrintfCString("%s  Ancestor mask layer %d:\n", aPrefix, uint32_t(i)).get();
+    nsAutoCString pfx(aPrefix);
+    pfx += "    ";
+    GetAncestorMaskLayerAt(i)->Dump(aStream, pfx.get(), aDumpHtml);
+  }
+
+#ifdef MOZ_DUMP_PAINTING
+  for (size_t i = 0; i < mExtraDumpInfo.Length(); i++) {
+    const nsCString& str = mExtraDumpInfo[i];
+    aStream << aPrefix << "  Info:\n" << str.get();
+  }
+#endif
+
+  if (ContainerLayer* container = AsContainerLayer()) {
+    AutoTArray<Layer*, 12> children;
+    if (aSorted) {
+      container->SortChildrenBy3DZOrder(children);
+    } else {
+      for (Layer* l = container->GetFirstChild(); l; l = l->GetNextSibling()) {
+        children.AppendElement(l);
+      }
+    }
+    nsAutoCString pfx(aPrefix);
+    pfx += "  ";
+    if (aDumpHtml) {
+      aStream << "<ul>";
+    }
+
+    for (Layer* child : children) {
+      child->Dump(aStream, pfx.get(), aDumpHtml, aSorted);
+    }
+
+    if (aDumpHtml) {
+      aStream << "</ul>";
+    }
+  }
+
+  if (aDumpHtml) {
+    aStream << "</li>";
+  }
+}
+
+void
+Layer::DumpSelf(std::stringstream& aStream, const char* aPrefix)
+{
+  PrintInfo(aStream, aPrefix);
+  aStream << "\n";
+}
+
+void
+Layer::Dump(layerscope::LayersPacket* aPacket, const void* aParent)
+{
+  DumpPacket(aPacket, aParent);
+
+  if (Layer* kid = GetFirstChild()) {
+    kid->Dump(aPacket, this);
+  }
+
+  if (Layer* next = GetNextSibling()) {
+    next->Dump(aPacket, aParent);
+  }
+}
+
+void
+Layer::SetDisplayListLog(const char* log)
+{
+  if (gfxUtils::DumpDisplayList()) {
+    mDisplayListLog = log;
+  }
+}
+
+void
+Layer::GetDisplayListLog(nsCString& log)
+{
+  log.SetLength(0);
+
+  if (gfxUtils::DumpDisplayList()) {
+    // This function returns a plain text string which consists of two things
+    //   1. DisplayList log.
+    //   2. Memory address of this layer.
+    // We know the target layer of each display item by information in #1.
+    // Here is an example of a Text display item line log in #1
+    //   Text p=0xa9850c00 f=0x0xaa405b00(.....
+    // f keeps the address of the target client layer of a display item.
+    // For LayerScope, display-item-to-client-layer mapping is not enough since
+    // LayerScope, which lives in the chrome process, knows only composite layers.
+    // As so, we need display-item-to-client-layer-to-layer-composite
+    // mapping. That's the reason we insert #2 into the log
+    log.AppendPrintf("0x%p\n%s",(void*) this, mDisplayListLog.get());
+  }
+}
+
+void
+Layer::Log(const char* aPrefix)
+{
+  if (!IsLogEnabled())
+    return;
+
+  LogSelf(aPrefix);
+
+  if (Layer* kid = GetFirstChild()) {
+    nsAutoCString pfx(aPrefix);
+    pfx += "  ";
+    kid->Log(pfx.get());
+  }
+
+  if (Layer* next = GetNextSibling())
+    next->Log(aPrefix);
+}
+
+void
+Layer::LogSelf(const char* aPrefix)
+{
+  if (!IsLogEnabled())
+    return;
+
+  std::stringstream ss;
+  PrintInfo(ss, aPrefix);
+  MOZ_LAYERS_LOG(("%s", ss.str().c_str()));
+
+  if (mMaskLayer) {
+    nsAutoCString pfx(aPrefix);
+    pfx += "   \\ MaskLayer ";
+    mMaskLayer->LogSelf(pfx.get());
+  }
+}
+
+void
+Layer::PrintInfo(std::stringstream& aStream, const char* aPrefix)
+{
+  aStream << aPrefix;
+  aStream << nsPrintfCString("%s%s (0x%p)", mManager->Name(), Name(), this).get();
+
+  layers::PrintInfo(aStream, AsLayerComposite());
+
+  if (mClipRect) {
+    AppendToString(aStream, *mClipRect, " [clip=", "]");
+  }
+  if (mScrolledClip) {
+    AppendToString(aStream, mScrolledClip->GetClipRect(), " [scrolled-clip=", "]");
+  }
+  if (1.0 != mPostXScale || 1.0 != mPostYScale) {
+    aStream << nsPrintfCString(" [postScale=%g, %g]", mPostXScale, mPostYScale).get();
+  }
+  if (!mTransform.IsIdentity()) {
+    AppendToString(aStream, mTransform, " [transform=", "]");
+  }
+  if (!GetEffectiveTransform().IsIdentity()) {
+    AppendToString(aStream, GetEffectiveTransform(), " [effective-transform=", "]");
+  }
+  if (mTransformIsPerspective) {
+    aStream << " [perspective]";
+  }
+  if (!mLayerBounds.IsEmpty()) {
+    AppendToString(aStream, mLayerBounds, " [bounds=", "]");
+  }
+  if (!mVisibleRegion.IsEmpty()) {
+    AppendToString(aStream, mVisibleRegion.ToUnknownRegion(), " [visible=", "]");
+  } else {
+    aStream << " [not visible]";
+  }
+  if (!mEventRegions.IsEmpty()) {
+    AppendToString(aStream, mEventRegions, " ", "");
+  }
+  if (1.0 != mOpacity) {
+    aStream << nsPrintfCString(" [opacity=%g]", mOpacity).get();
+  }
+  if (IsOpaque()) {
+    aStream << " [opaqueContent]";
+  }
+  if (GetContentFlags() & CONTENT_COMPONENT_ALPHA) {
+    aStream << " [componentAlpha]";
+  }
+  if (GetContentFlags() & CONTENT_BACKFACE_HIDDEN) {
+    aStream << " [backfaceHidden]";
+  }
+  if (Extend3DContext()) {
+    aStream << " [extend3DContext]";
+  }
+  if (Combines3DTransformWithAncestors()) {
+    aStream << " [combines3DTransformWithAncestors]";
+  }
+  if (Is3DContextLeaf()) {
+    aStream << " [is3DContextLeaf]";
+  }
+  if (IsScrollbarContainer()) {
+    aStream << " [scrollbar]";
+  }
+  if (GetScrollbarDirection() == VERTICAL) {
+    aStream << nsPrintfCString(" [vscrollbar=%lld]", GetScrollbarTargetContainerId()).get();
+  }
+  if (GetScrollbarDirection() == HORIZONTAL) {
+    aStream << nsPrintfCString(" [hscrollbar=%lld]", GetScrollbarTargetContainerId()).get();
+  }
+  if (GetIsFixedPosition()) {
+    LayerPoint anchor = GetFixedPositionAnchor();
+    aStream << nsPrintfCString(" [isFixedPosition scrollId=%lld sides=0x%x anchor=%s]",
+                     GetFixedPositionScrollContainerId(),
+                     GetFixedPositionSides(),
+                     ToString(anchor).c_str()).get();
+  }
+  if (GetIsStickyPosition()) {
+    aStream << nsPrintfCString(" [isStickyPosition scrollId=%d outer=(%.3f,%.3f)-(%.3f,%.3f) "
+                     "inner=(%.3f,%.3f)-(%.3f,%.3f)]", mStickyPositionData->mScrollId,
+                     mStickyPositionData->mOuter.x, mStickyPositionData->mOuter.y,
+                     mStickyPositionData->mOuter.XMost(), mStickyPositionData->mOuter.YMost(),
+                     mStickyPositionData->mInner.x, mStickyPositionData->mInner.y,
+                     mStickyPositionData->mInner.XMost(), mStickyPositionData->mInner.YMost()).get();
+  }
+  if (mMaskLayer) {
+    aStream << nsPrintfCString(" [mMaskLayer=%p]", mMaskLayer.get()).get();
+  }
+  for (uint32_t i = 0; i < mScrollMetadata.Length(); i++) {
+    if (!mScrollMetadata[i].IsDefault()) {
+      aStream << nsPrintfCString(" [metrics%d=", i).get();
+      AppendToString(aStream, mScrollMetadata[i], "", "]");
+    }
+  }
+}
+
+// The static helper function sets the transform matrix into the packet
+static void
+DumpTransform(layerscope::LayersPacket::Layer::Matrix* aLayerMatrix, const Matrix4x4& aMatrix)
+{
+  aLayerMatrix->set_is2d(aMatrix.Is2D());
+  if (aMatrix.Is2D()) {
+    Matrix m = aMatrix.As2D();
+    aLayerMatrix->set_isid(m.IsIdentity());
+    if (!m.IsIdentity()) {
+      aLayerMatrix->add_m(m._11), aLayerMatrix->add_m(m._12);
+      aLayerMatrix->add_m(m._21), aLayerMatrix->add_m(m._22);
+      aLayerMatrix->add_m(m._31), aLayerMatrix->add_m(m._32);
+    }
+  } else {
+    aLayerMatrix->add_m(aMatrix._11), aLayerMatrix->add_m(aMatrix._12);
+    aLayerMatrix->add_m(aMatrix._13), aLayerMatrix->add_m(aMatrix._14);
+    aLayerMatrix->add_m(aMatrix._21), aLayerMatrix->add_m(aMatrix._22);
+    aLayerMatrix->add_m(aMatrix._23), aLayerMatrix->add_m(aMatrix._24);
+    aLayerMatrix->add_m(aMatrix._31), aLayerMatrix->add_m(aMatrix._32);
+    aLayerMatrix->add_m(aMatrix._33), aLayerMatrix->add_m(aMatrix._34);
+    aLayerMatrix->add_m(aMatrix._41), aLayerMatrix->add_m(aMatrix._42);
+    aLayerMatrix->add_m(aMatrix._43), aLayerMatrix->add_m(aMatrix._44);
+  }
+}
+
+// The static helper function sets the IntRect into the packet
+template <typename T, typename Sub, typename Point, typename SizeT, typename MarginT>
+static void
+DumpRect(layerscope::LayersPacket::Layer::Rect* aLayerRect,
+         const BaseRect<T, Sub, Point, SizeT, MarginT>& aRect)
+{
+  aLayerRect->set_x(aRect.x);
+  aLayerRect->set_y(aRect.y);
+  aLayerRect->set_w(aRect.width);
+  aLayerRect->set_h(aRect.height);
+}
+
+// The static helper function sets the nsIntRegion into the packet
+static void
+DumpRegion(layerscope::LayersPacket::Layer::Region* aLayerRegion, const nsIntRegion& aRegion)
+{
+  for (auto iter = aRegion.RectIter(); !iter.Done(); iter.Next()) {
+    DumpRect(aLayerRegion->add_r(), iter.Get());
+  }
+}
+
+void
+Layer::DumpPacket(layerscope::LayersPacket* aPacket, const void* aParent)
+{
+  // Add a new layer (UnknownLayer)
+  using namespace layerscope;
+  LayersPacket::Layer* layer = aPacket->add_layer();
+  // Basic information
+  layer->set_type(LayersPacket::Layer::UnknownLayer);
+  layer->set_ptr(reinterpret_cast<uint64_t>(this));
+  layer->set_parentptr(reinterpret_cast<uint64_t>(aParent));
+  // Shadow
+  if (LayerComposite* lc = AsLayerComposite()) {
+    LayersPacket::Layer::Shadow* s = layer->mutable_shadow();
+    if (const Maybe<ParentLayerIntRect>& clipRect = lc->GetShadowClipRect()) {
+      DumpRect(s->mutable_clip(), *clipRect);
+    }
+    if (!lc->GetShadowBaseTransform().IsIdentity()) {
+      DumpTransform(s->mutable_transform(), lc->GetShadowBaseTransform());
+    }
+    if (!lc->GetShadowVisibleRegion().IsEmpty()) {
+      DumpRegion(s->mutable_vregion(), lc->GetShadowVisibleRegion().ToUnknownRegion());
+    }
+  }
+  // Clip
+  if (mClipRect) {
+    DumpRect(layer->mutable_clip(), *mClipRect);
+  }
+  // Transform
+  if (!mTransform.IsIdentity()) {
+    DumpTransform(layer->mutable_transform(), mTransform);
+  }
+  // Visible region
+  if (!mVisibleRegion.ToUnknownRegion().IsEmpty()) {
+    DumpRegion(layer->mutable_vregion(), mVisibleRegion.ToUnknownRegion());
+  }
+  // EventRegions
+  if (!mEventRegions.IsEmpty()) {
+    const EventRegions &e = mEventRegions;
+    if (!e.mHitRegion.IsEmpty()) {
+      DumpRegion(layer->mutable_hitregion(), e.mHitRegion);
+    }
+    if (!e.mDispatchToContentHitRegion.IsEmpty()) {
+      DumpRegion(layer->mutable_dispatchregion(), e.mDispatchToContentHitRegion);
+    }
+    if (!e.mNoActionRegion.IsEmpty()) {
+      DumpRegion(layer->mutable_noactionregion(), e.mNoActionRegion);
+    }
+    if (!e.mHorizontalPanRegion.IsEmpty()) {
+      DumpRegion(layer->mutable_hpanregion(), e.mHorizontalPanRegion);
+    }
+    if (!e.mVerticalPanRegion.IsEmpty()) {
+      DumpRegion(layer->mutable_vpanregion(), e.mVerticalPanRegion);
+    }
+  }
+  // Opacity
+  layer->set_opacity(mOpacity);
+  // Content opaque
+  layer->set_copaque(static_cast<bool>(GetContentFlags() & CONTENT_OPAQUE));
+  // Component alpha
+  layer->set_calpha(static_cast<bool>(GetContentFlags() & CONTENT_COMPONENT_ALPHA));
+  // Vertical or horizontal bar
+  if (GetScrollbarDirection() != NONE) {
+    layer->set_direct(GetScrollbarDirection() == VERTICAL ?
+                      LayersPacket::Layer::VERTICAL :
+                      LayersPacket::Layer::HORIZONTAL);
+    layer->set_barid(GetScrollbarTargetContainerId());
+  }
+
+  // Mask layer
+  if (mMaskLayer) {
+    layer->set_mask(reinterpret_cast<uint64_t>(mMaskLayer.get()));
+  }
+
+  // DisplayList log.
+  if (mDisplayListLog.Length() > 0) {
+    layer->set_displaylistloglength(mDisplayListLog.Length());
+    auto compressedData =
+      MakeUnique<char[]>(LZ4::maxCompressedSize(mDisplayListLog.Length()));
+    int compressedSize = LZ4::compress((char*)mDisplayListLog.get(),
+                                       mDisplayListLog.Length(),
+                                       compressedData.get());
+    layer->set_displaylistlog(compressedData.get(), compressedSize);
+  }
+}
+
+bool
+Layer::IsBackfaceHidden()
+{
+  if (GetContentFlags() & CONTENT_BACKFACE_HIDDEN) {
+    Layer* container = AsContainerLayer() ? this : GetParent();
+    if (container) {
+      // The effective transform can include non-preserve-3d parent
+      // transforms, since we don't always require an intermediate.
+      if (container->Extend3DContext() || container->Is3DContextLeaf()) {
+        return container->GetEffectiveTransform().IsBackfaceVisible();
+      }
+      return container->GetBaseTransform().IsBackfaceVisible();
+    }
+  }
+  return false;
+}
+
+UniquePtr<LayerUserData>
+Layer::RemoveUserData(void* aKey)
+{
+  UniquePtr<LayerUserData> d(static_cast<LayerUserData*>(mUserData.Remove(static_cast<gfx::UserDataKey*>(aKey))));
+  return d;
+}
+
+void
+PaintedLayer::PrintInfo(std::stringstream& aStream, const char* aPrefix)
+{
+  Layer::PrintInfo(aStream, aPrefix);
+  if (!mValidRegion.IsEmpty()) {
+    AppendToString(aStream, mValidRegion, " [valid=", "]");
+  }
+}
+
+void
+PaintedLayer::DumpPacket(layerscope::LayersPacket* aPacket, const void* aParent)
+{
+  Layer::DumpPacket(aPacket, aParent);
+  // get this layer data
+  using namespace layerscope;
+  LayersPacket::Layer* layer = aPacket->mutable_layer(aPacket->layer_size()-1);
+  layer->set_type(LayersPacket::Layer::PaintedLayer);
+  if (!mValidRegion.IsEmpty()) {
+    DumpRegion(layer->mutable_valid(), mValidRegion);
+  }
+}
+
+void
+ContainerLayer::PrintInfo(std::stringstream& aStream, const char* aPrefix)
+{
+  Layer::PrintInfo(aStream, aPrefix);
+  if (UseIntermediateSurface()) {
+    aStream << " [usesTmpSurf]";
+  }
+  if (1.0 != mPreXScale || 1.0 != mPreYScale) {
+    aStream << nsPrintfCString(" [preScale=%g, %g]", mPreXScale, mPreYScale).get();
+  }
+  if (mScaleToResolution) {
+    aStream << nsPrintfCString(" [presShellResolution=%g]", mPresShellResolution).get();
+  }
+  if (mEventRegionsOverride & EventRegionsOverride::ForceDispatchToContent) {
+    aStream << " [force-dtc]";
+  }
+  if (mEventRegionsOverride & EventRegionsOverride::ForceEmptyHitRegion) {
+    aStream << " [force-ehr]";
+  }
+}
+
+void
+ContainerLayer::DumpPacket(layerscope::LayersPacket* aPacket, const void* aParent)
+{
+  Layer::DumpPacket(aPacket, aParent);
+  // Get this layer data
+  using namespace layerscope;
+  LayersPacket::Layer* layer = aPacket->mutable_layer(aPacket->layer_size()-1);
+  layer->set_type(LayersPacket::Layer::ContainerLayer);
+}
+
+void
+ColorLayer::PrintInfo(std::stringstream& aStream, const char* aPrefix)
+{
+  Layer::PrintInfo(aStream, aPrefix);
+  AppendToString(aStream, mColor, " [color=", "]");
+  AppendToString(aStream, mBounds, " [bounds=", "]");
+}
+
+void
+ColorLayer::DumpPacket(layerscope::LayersPacket* aPacket, const void* aParent)
+{
+  Layer::DumpPacket(aPacket, aParent);
+  // Get this layer data
+  using namespace layerscope;
+  LayersPacket::Layer* layer = aPacket->mutable_layer(aPacket->layer_size()-1);
+  layer->set_type(LayersPacket::Layer::ColorLayer);
+  layer->set_color(mColor.ToABGR());
+}
+
+CanvasLayer::CanvasLayer(LayerManager* aManager, void* aImplData)
+  : Layer(aManager, aImplData)
+  , mPreTransCallback(nullptr)
+  , mPreTransCallbackData(nullptr)
+  , mPostTransCallback(nullptr)
+  , mPostTransCallbackData(nullptr)
+  , mSamplingFilter(gfx::SamplingFilter::GOOD)
+  , mDirty(false)
+{}
+
+CanvasLayer::~CanvasLayer()
+{}
+
+void
+CanvasLayer::PrintInfo(std::stringstream& aStream, const char* aPrefix)
+{
+  Layer::PrintInfo(aStream, aPrefix);
+  if (mSamplingFilter != SamplingFilter::GOOD) {
+    AppendToString(aStream, mSamplingFilter, " [filter=", "]");
+  }
+}
+
+// This help function is used to assign the correct enum value
+// to the packet
+static void
+DumpFilter(layerscope::LayersPacket::Layer* aLayer,
+           const SamplingFilter& aSamplingFilter)
+{
+  using namespace layerscope;
+  switch (aSamplingFilter) {
+    case SamplingFilter::GOOD:
+      aLayer->set_filter(LayersPacket::Layer::FILTER_GOOD);
+      break;
+    case SamplingFilter::LINEAR:
+      aLayer->set_filter(LayersPacket::Layer::FILTER_LINEAR);
+      break;
+    case SamplingFilter::POINT:
+      aLayer->set_filter(LayersPacket::Layer::FILTER_POINT);
+      break;
+    default:
+      // ignore it
+      break;
+  }
+}
+
+void
+CanvasLayer::DumpPacket(layerscope::LayersPacket* aPacket, const void* aParent)
+{
+  Layer::DumpPacket(aPacket, aParent);
+  // Get this layer data
+  using namespace layerscope;
+  LayersPacket::Layer* layer = aPacket->mutable_layer(aPacket->layer_size()-1);
+  layer->set_type(LayersPacket::Layer::CanvasLayer);
+  DumpFilter(layer, mSamplingFilter);
+}
+
+void
+ImageLayer::PrintInfo(std::stringstream& aStream, const char* aPrefix)
+{
+  Layer::PrintInfo(aStream, aPrefix);
+  if (mSamplingFilter != SamplingFilter::GOOD) {
+    AppendToString(aStream, mSamplingFilter, " [filter=", "]");
+  }
+}
+
+void
+ImageLayer::DumpPacket(layerscope::LayersPacket* aPacket, const void* aParent)
+{
+  Layer::DumpPacket(aPacket, aParent);
+  // Get this layer data
+  using namespace layerscope;
+  LayersPacket::Layer* layer = aPacket->mutable_layer(aPacket->layer_size()-1);
+  layer->set_type(LayersPacket::Layer::ImageLayer);
+  DumpFilter(layer, mSamplingFilter);
+}
+
+void
+RefLayer::PrintInfo(std::stringstream& aStream, const char* aPrefix)
+{
+  ContainerLayer::PrintInfo(aStream, aPrefix);
+  if (0 != mId) {
+    AppendToString(aStream, mId, " [id=", "]");
+  }
+}
+
+void
+RefLayer::DumpPacket(layerscope::LayersPacket* aPacket, const void* aParent)
+{
+  Layer::DumpPacket(aPacket, aParent);
+  // Get this layer data
+  using namespace layerscope;
+  LayersPacket::Layer* layer = aPacket->mutable_layer(aPacket->layer_size()-1);
+  layer->set_type(LayersPacket::Layer::RefLayer);
+  layer->set_refid(mId);
+}
+
+void
+ReadbackLayer::PrintInfo(std::stringstream& aStream, const char* aPrefix)
+{
+  Layer::PrintInfo(aStream, aPrefix);
+  AppendToString(aStream, mSize, " [size=", "]");
+  if (mBackgroundLayer) {
+    AppendToString(aStream, mBackgroundLayer, " [backgroundLayer=", "]");
+    AppendToString(aStream, mBackgroundLayerOffset, " [backgroundOffset=", "]");
+  } else if (mBackgroundColor.a == 1.f) {
+    AppendToString(aStream, mBackgroundColor, " [backgroundColor=", "]");
+  } else {
+    aStream << " [nobackground]";
+  }
+}
+
+void
+ReadbackLayer::DumpPacket(layerscope::LayersPacket* aPacket, const void* aParent)
+{
+  Layer::DumpPacket(aPacket, aParent);
+  // Get this layer data
+  using namespace layerscope;
+  LayersPacket::Layer* layer = aPacket->mutable_layer(aPacket->layer_size()-1);
+  layer->set_type(LayersPacket::Layer::ReadbackLayer);
+  LayersPacket::Layer::Size* size = layer->mutable_size();
+  size->set_w(mSize.width);
+  size->set_h(mSize.height);
+}
+
+//--------------------------------------------------
+// LayerManager
+
+void
+LayerManager::Dump(std::stringstream& aStream, const char* aPrefix,
+                   bool aDumpHtml, bool aSorted)
+{
+#ifdef MOZ_DUMP_PAINTING
+  if (aDumpHtml) {
+    aStream << "<ul><li>";
+  }
+#endif
+  DumpSelf(aStream, aPrefix, aSorted);
+
+  nsAutoCString pfx(aPrefix);
+  pfx += "  ";
+  if (!GetRoot()) {
+    aStream << nsPrintfCString("%s(null)", pfx.get()).get();
+    if (aDumpHtml) {
+      aStream << "</li></ul>";
+    }
+    return;
+  }
+
+  if (aDumpHtml) {
+    aStream << "<ul>";
+  }
+  GetRoot()->Dump(aStream, pfx.get(), aDumpHtml);
+  if (aDumpHtml) {
+    aStream << "</ul></li></ul>";
+  }
+  aStream << "\n";
+}
+
+void
+LayerManager::DumpSelf(std::stringstream& aStream, const char* aPrefix, bool aSorted)
+{
+  PrintInfo(aStream, aPrefix);
+  aStream << " --- in " << (aSorted ? "3D-sorted rendering order" : "content order");
+  aStream << "\n";
+}
+
+void
+LayerManager::Dump(bool aSorted)
+{
+  std::stringstream ss;
+  Dump(ss, "", false, aSorted);
+  print_stderr(ss);
+}
+
+void
+LayerManager::Dump(layerscope::LayersPacket* aPacket)
+{
+  DumpPacket(aPacket);
+
+  if (GetRoot()) {
+    GetRoot()->Dump(aPacket, this);
+  }
+}
+
+void
+LayerManager::Log(const char* aPrefix)
+{
+  if (!IsLogEnabled())
+    return;
+
+  LogSelf(aPrefix);
+
+  nsAutoCString pfx(aPrefix);
+  pfx += "  ";
+  if (!GetRoot()) {
+    MOZ_LAYERS_LOG(("%s(null)", pfx.get()));
+    return;
+  }
+
+  GetRoot()->Log(pfx.get());
+}
+
+void
+LayerManager::LogSelf(const char* aPrefix)
+{
+  nsAutoCString str;
+  std::stringstream ss;
+  PrintInfo(ss, aPrefix);
+  MOZ_LAYERS_LOG(("%s", ss.str().c_str()));
+}
+
+void
+LayerManager::PrintInfo(std::stringstream& aStream, const char* aPrefix)
+{
+  aStream << aPrefix << nsPrintfCString("%sLayerManager (0x%p)", Name(), this).get();
+}
+
+void
+LayerManager::DumpPacket(layerscope::LayersPacket* aPacket)
+{
+  using namespace layerscope;
+  // Add a new layer data (LayerManager)
+  LayersPacket::Layer* layer = aPacket->add_layer();
+  layer->set_type(LayersPacket::Layer::LayerManager);
+  layer->set_ptr(reinterpret_cast<uint64_t>(this));
+  // Layer Tree Root
+  layer->set_parentptr(0);
+}
+
+/*static*/ bool
+LayerManager::IsLogEnabled()
+{
+  return MOZ_LOG_TEST(GetLog(), LogLevel::Debug);
+}
+
+void
+LayerManager::SetPendingScrollUpdateForNextTransaction(FrameMetrics::ViewID aScrollId,
+                                                       const ScrollUpdateInfo& aUpdateInfo)
+{
+  mPendingScrollUpdates[aScrollId] = aUpdateInfo;
+}
+
+Maybe<ScrollUpdateInfo>
+LayerManager::GetPendingScrollInfoUpdate(FrameMetrics::ViewID aScrollId)
+{
+  auto it = mPendingScrollUpdates.find(aScrollId);
+  if (it != mPendingScrollUpdates.end()) {
+    return Some(it->second);
+  }
+  return Nothing();
+}
+
+void
+LayerManager::ClearPendingScrollInfoUpdate()
+{
+  mPendingScrollUpdates.clear();
+}
+
+void
+PrintInfo(std::stringstream& aStream, LayerComposite* aLayerComposite)
+{
+  if (!aLayerComposite) {
+    return;
+  }
+  if (const Maybe<ParentLayerIntRect>& clipRect = aLayerComposite->GetShadowClipRect()) {
+    AppendToString(aStream, *clipRect, " [shadow-clip=", "]");
+  }
+  if (!aLayerComposite->GetShadowBaseTransform().IsIdentity()) {
+    AppendToString(aStream, aLayerComposite->GetShadowBaseTransform(), " [shadow-transform=", "]");
+  }
+  if (!aLayerComposite->GetShadowVisibleRegion().IsEmpty()) {
+    AppendToString(aStream, aLayerComposite->GetShadowVisibleRegion().ToUnknownRegion(), " [shadow-visible=", "]");
+  }
+}
+
+void
+SetAntialiasingFlags(Layer* aLayer, DrawTarget* aTarget)
+{
+  bool permitSubpixelAA = !(aLayer->GetContentFlags() & Layer::CONTENT_DISABLE_SUBPIXEL_AA);
+  if (aTarget->IsCurrentGroupOpaque()) {
+    aTarget->SetPermitSubpixelAA(permitSubpixelAA);
+    return;
+  }
+
+  const IntRect& bounds = aLayer->GetVisibleRegion().ToUnknownRegion().GetBounds();
+  gfx::Rect transformedBounds = aTarget->GetTransform().TransformBounds(gfx::Rect(Float(bounds.x), Float(bounds.y),
+                                                                                  Float(bounds.width), Float(bounds.height)));
+  transformedBounds.RoundOut();
+  IntRect intTransformedBounds;
+  transformedBounds.ToIntRect(&intTransformedBounds);
+  permitSubpixelAA &= !(aLayer->GetContentFlags() & Layer::CONTENT_COMPONENT_ALPHA) ||
+                      aTarget->GetOpaqueRect().Contains(intTransformedBounds);
+  aTarget->SetPermitSubpixelAA(permitSubpixelAA);
+}
+
+IntRect
+ToOutsideIntRect(const gfxRect &aRect)
+{
+  return IntRect::RoundOut(aRect.x, aRect.y, aRect.width, aRect.height);
+}
+
+} // namespace layers
+} // namespace mozilla