gfx/layers/Layers.cpp
author Boris Chiou <boris.chiou@gmail.com>
Mon, 18 Mar 2019 18:04:48 +0000
changeset 464936 6c55b82deb9ba9b5924ef6bfdecdffaf9f42307a
parent 461933 5b5e6a9942777d6faee07db57fd6b14d465b3ab3
child 465585 c09a51622e988e81077c75e3aaa5a49df66284b3
permissions -rw-r--r--
Bug 1425837 - Part 3: Don't store AnimationArray (a.k.a. AnimationInfo::mAnimations) on the compositor thread. r=birtles The original implementation about "setting animations" is a little bit hard to read. In `SetAnimations()`, we create a new intermediate data, `AnimData`, and we mutate the original animations. And then iterate this mutated animations & intermediate data for sampling. In this bug, we are planning to group the AnimData as a useful data structure for supporting multiple properties transform-like animations, so it seems the structure of original animations may be hard to use after that. Therefore, we decide to do some reworks on this: First, we do renames, 1. InfalliableTArray to nsTArray. (They are the same.) 2. AnimData to PropertyAnimation. 3. SetAnimations() to ExtractAnimations(), which returns nsTArray<PropertyAnimationGroup>. Each entry in the array is for one property. In this patch, there is only one entry. We will extend this to multiple entries in the next patch. And then rework `ExtractAnimations()`, which stores all the necessary data in `PropertyAnimationGroup`. For WR, we store this in `CompositorAnimationStorage`. For non-WR, we store it in `AnimationInfo`. So we can just use this organized data structure for supporting multiple properties animations. (See the next patch.) Depends on D22563 Differential Revision: https://phabricator.services.mozilla.com/D23062

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "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/IntegerPrintfMacros.h"
#include "mozilla/Telemetry.h"  // for Accumulate
#include "mozilla/ToString.h"
#include "mozilla/gfx/2D.h"        // for DrawTarget
#include "mozilla/gfx/BaseSize.h"  // for BaseSize
#include "mozilla/gfx/Matrix.h"    // for Matrix4x4
#include "mozilla/gfx/Polygon.h"   // for Polygon
#include "mozilla/layers/AsyncCanvasRenderer.h"
#include "mozilla/layers/BSPTree.h"             // for BSPTree
#include "mozilla/layers/CompositableClient.h"  // for CompositableClient
#include "mozilla/layers/Compositor.h"          // for Compositor
#include "mozilla/layers/CompositorTypes.h"
#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 "nsDisplayList.h"    // for nsDisplayItem
#include "nsPrintfCString.h"  // for nsPrintfCString
#include "protobuf/LayerScopePacket.pb.h"
#include "mozilla/Compression.h"
#include "TreeTraversal.h"  // for ForEachNode

#include <list>
#include <set>

uint8_t gLayerManagerLayerBuilder;

namespace mozilla {
namespace layers {

typedef ScrollableLayerGuid::ViewID ViewID;

using namespace mozilla::gfx;
using namespace mozilla::Compression;

//--------------------------------------------------
// LayerManager

/* static */ mozilla::LogModule* LayerManager::GetLog() {
  static LazyLogModule sLog("Layers");
  return sLog;
}

ScrollableLayerGuid::ViewID LayerManager::GetRootScrollableLayerId() {
  if (!mRoot) {
    return ScrollableLayerGuid::NULL_SCROLL_ID;
  }

  LayerMetricsWrapper layerMetricsRoot = LayerMetricsWrapper(mRoot);

  LayerMetricsWrapper rootScrollableLayerMetrics =
      BreadthFirstSearch<ForwardIterator>(
          layerMetricsRoot, [](LayerMetricsWrapper aLayerMetrics) {
            return aLayerMetrics.Metrics().IsScrollable();
          });

  return rootScrollableLayerMetrics.IsValid()
             ? rootScrollableLayerMetrics.Metrics().GetScrollId()
             : ScrollableLayerGuid::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();
}

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;
}

void LayerManager::PayloadPresented() {
  if (mPayload.Length()) {
    TimeStamp presented = TimeStamp::Now();
    for (CompositionPayload& payload : mPayload) {
#if MOZ_GECKO_PROFILER
      if (profiler_is_active()) {
        nsPrintfCString marker(
            "Payload Presented, type: %d latency: %dms\n",
            int32_t(payload.mType),
            int32_t((presented - payload.mTimeStamp).ToMilliseconds()));
        profiler_add_marker(marker.get(), JS::ProfilingCategoryPair::GRAPHICS);
      }
#endif

      if (payload.mType == CompositionPayloadType::eKeyPress) {
        Telemetry::AccumulateTimeDelta(
            mozilla::Telemetry::KEYPRESS_PRESENT_LATENCY, payload.mTimeStamp,
            presented);
      }
    }
  }
}

//--------------------------------------------------
// Layer

Layer::Layer(LayerManager* aManager, void* aImplData)
    : mManager(aManager),
      mParent(nullptr),
      mNextSibling(nullptr),
      mPrevSibling(nullptr),
      mImplData(aImplData),
      mUseTileSourceRect(false)
#ifdef DEBUG
      ,
      mDebugColorIndex(0)
#endif
{
}

Layer::~Layer() {}

void Layer::SetCompositorAnimations(
    const CompositorAnimations& aCompositorAnimations) {
  MOZ_LAYERS_LOG_IF_SHADOWABLE(
      this, ("Layer::Mutated(%p) SetCompositorAnimations with id=%" PRIu64,
             this, mAnimationInfo.GetCompositorAnimationsId()));

  mAnimationInfo.SetCompositorAnimations(aCompositorAnimations);

  Mutated();
}

void Layer::ClearCompositorAnimations() {
  MOZ_LAYERS_LOG_IF_SHADOWABLE(
      this, ("Layer::Mutated(%p) ClearCompositorAnimations with id=%" PRIu64,
             this, mAnimationInfo.GetCompositorAnimationsId()));

  mAnimationInfo.ClearAnimations();

  Mutated();
}

void Layer::StartPendingAnimations(const TimeStamp& aReadyTime) {
  ForEachNode<ForwardIterator>(this, [&aReadyTime](Layer* layer) {
    if (layer->mAnimationInfo.StartPendingAnimations(aReadyTime)) {
      layer->Mutated();
    }
  });
}

void Layer::SetAsyncPanZoomController(uint32_t aIndex,
                                      AsyncPanZoomController* controller) {
  MOZ_ASSERT(aIndex < GetScrollMetadataCount());
  // We should never be setting an APZC on a non-scrollable layer
  MOZ_ASSERT(!controller || GetFrameMetrics(aIndex).IsScrollable());
  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 (HostLayer* shadow = AsHostLayer()) {
    return shadow->GetShadowClipRect();
  }
  return GetClipRect();
}

const LayerIntRegion& Layer::GetLocalVisibleRegion() {
  if (HostLayer* shadow = AsHostLayer()) {
    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;
    }

    if (l->GetParent() && l->GetParent()->AsRefLayer()) {
      return false;
    }
  }
  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()) {
    // 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 {
  const Maybe<LayerClip> clip = mSimpleAttrs.GetScrolledClip();
  return clip ? Some(clip->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::HasRootScrollableFrameMetrics() const {
  for (uint32_t i = 0; i < GetScrollMetadataCount(); i++) {
    if (GetFrameMetrics(i).IsScrollable() &&
        GetFrameMetrics(i).IsRootContent()) {
      return true;
    }
  }
  return false;
}

bool Layer::IsScrollableWithoutContent() const {
  // A scrollable container layer with no children
  return AsContainerLayer() && HasScrollableFrameMetrics() && !GetFirstChild();
}

Matrix4x4 Layer::GetTransform() const {
  Matrix4x4 transform = mSimpleAttrs.GetTransform();
  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 (HostLayer* shadow = AsHostLayer()) {
    return shadow->GetShadowTransform();
  }
  return GetTransform();
}

const LayerToParentLayerMatrix4x4 Layer::GetLocalTransformTyped() {
  return ViewAs<LayerToParentLayerMatrix4x4>(GetLocalTransform());
}

bool Layer::IsScrollbarContainer() const {
  const ScrollbarData& data = GetScrollbarData();
  return (data.mScrollbarLayerType == ScrollbarLayerType::Container)
             ? data.mDirection.isSome()
             : false;
}

bool Layer::HasTransformAnimation() const {
  return mAnimationInfo.HasTransformAnimation();
}

void Layer::ApplyPendingUpdatesForThisTransaction() {
  if (mPendingTransform && *mPendingTransform != mSimpleAttrs.GetTransform()) {
    MOZ_LAYERS_LOG_IF_SHADOWABLE(
        this, ("Layer::Mutated(%p) PendingUpdatesForThisTransaction", this));
    mSimpleAttrs.SetTransform(*mPendingTransform);
    MutatedSimple();
  }
  mPendingTransform = nullptr;

  if (mAnimationInfo.ApplyPendingUpdatesForThisTransaction()) {
    MOZ_LAYERS_LOG_IF_SHADOWABLE(
        this, ("Layer::Mutated(%p) PendingUpdatesForThisTransaction", this));
    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 = mSimpleAttrs.GetOpacity();
  if (HostLayer* shadow = AsHostLayer()) 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 (mSimpleAttrs.GetMixBlendMode() != CompositionOp::OP_OVER)
    return mSimpleAttrs.GetMixBlendMode();
  for (ContainerLayer* c = GetParent(); c && !c->UseIntermediateSurface();
       c = c->GetParent()) {
    if (c->mSimpleAttrs.GetMixBlendMode() != CompositionOp::OP_OVER)
      return c->mSimpleAttrs.GetMixBlendMode();
  }

  return mSimpleAttrs.GetMixBlendMode();
}

Matrix4x4 Layer::ComputeTransformToPreserve3DRoot() {
  Matrix4x4 transform = GetLocalTransform();
  for (Layer* layer = GetParent(); layer && layer->Extend3DContext();
       layer = layer->GetParent()) {
    transform = transform * layer->GetLocalTransform();
  }
  return transform;
}

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),
      mUseIntermediateSurface(false),
      mSupportsComponentAlphaChildren(false),
      mMayHaveReadbackChild(false),
      mChildrenChanged(false) {}

ContainerLayer::~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;
}

void ContainerLayer::RemoveAllChildren() {
  // Optimizes "while (mFirstChild) ContainerLayer::RemoveChild(mFirstChild);"
  Layer* current = mFirstChild;

  // This is inlining DidRemoveChild() on each layer; we can skip the calls
  // to NotifyPaintedLayerRemoved as it gets taken care of when as we call
  // NotifyRemoved prior to removing any layers.
  while (current) {
    Layer* next = current->GetNextSibling();
    if (current->GetType() == TYPE_READBACK) {
      static_cast<ReadbackLayer*>(current)->NotifyRemoved();
    }
    current = next;
  }

  current = mFirstChild;
  mFirstChild = nullptr;
  while (current) {
    MOZ_ASSERT(!current->GetPrevSibling());

    Layer* next = current->GetNextSibling();
    current->SetParent(nullptr);
    current->SetNextSibling(nullptr);
    if (next) {
      next->SetPrevSibling(nullptr);
    }
    NS_RELEASE(current);
    current = next;
  }
}

// Note that ContainerLayer::RemoveAllChildren is an optimized
// version of this code; if you make changes to ContainerLayer::RemoveChild
// consider whether the matching changes need to be made to
// ContainerLayer::RemoveAllChildren
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);
}

bool ContainerLayer::Creates3DContextWithExtendingChildren() {
  if (Extend3DContext()) {
    return false;
  }
  for (Layer* child = GetFirstChild(); child; child = child->GetNextSibling()) {
    if (child->Extend3DContext()) {
      return true;
    }
  }
  return false;
}

RenderTargetIntRect ContainerLayer::GetIntermediateSurfaceRect() {
  NS_ASSERTION(mUseIntermediateSurface, "Must have intermediate surface");
  LayerIntRect bounds = GetLocalVisibleRegion().GetBounds();
  return RenderTargetIntRect::FromUnknownRect(bounds.ToUnknownRect());
}

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;
    }
    aToSort.AppendElement(layer);
    return TraversalFlag::Skip;
  });
}

static nsTArray<LayerPolygon> SortLayersWithBSPTree(nsTArray<Layer*>& aArray) {
  std::list<LayerPolygon> inputLayers;

  // Build a list of polygons to be sorted.
  for (Layer* layer : aArray) {
    // Ignore invisible layers.
    if (!layer->IsVisible()) {
      continue;
    }

    const gfx::IntRect& bounds =
        layer->GetLocalVisibleRegion().GetBounds().ToUnknownRect();

    const gfx::Matrix4x4& transform = layer->GetEffectiveTransform();

    if (transform.IsSingular()) {
      // Transform cannot be inverted.
      continue;
    }

    gfx::Polygon polygon = gfx::Polygon::FromRect(gfx::Rect(bounds));

    // Transform the polygon to screen space.
    polygon.TransformToScreenSpace(transform);

    if (polygon.GetPoints().Length() >= 3) {
      inputLayers.push_back(LayerPolygon(layer, std::move(polygon)));
    }
  }

  if (inputLayers.empty()) {
    return nsTArray<LayerPolygon>();
  }

  // Build a BSP tree from the list of polygons.
  BSPTree tree(inputLayers);

  nsTArray<LayerPolygon> orderedLayers(tree.GetDrawOrder());

  // Transform the polygons back to layer space.
  for (LayerPolygon& layerPolygon : orderedLayers) {
    gfx::Matrix4x4 inverse =
        layerPolygon.layer->GetEffectiveTransform().Inverse();

    MOZ_ASSERT(layerPolygon.geometry);
    layerPolygon.geometry->TransformToLayerSpace(inverse);
  }

  return orderedLayers;
}

static nsTArray<LayerPolygon> StripLayerGeometry(
    const nsTArray<LayerPolygon>& aLayers) {
  nsTArray<LayerPolygon> layers;
  std::set<Layer*> uniqueLayers;

  for (const LayerPolygon& layerPolygon : aLayers) {
    auto result = uniqueLayers.insert(layerPolygon.layer);

    if (result.second) {
      // Layer was added to the set.
      layers.AppendElement(LayerPolygon(layerPolygon.layer));
    }
  }

  return layers;
}

nsTArray<LayerPolygon> ContainerLayer::SortChildrenBy3DZOrder(
    SortMode aSortMode) {
  AutoTArray<Layer*, 10> toSort;
  nsTArray<LayerPolygon> drawOrder;

  for (Layer* layer = GetFirstChild(); layer; layer = layer->GetNextSibling()) {
    ContainerLayer* container = layer->AsContainerLayer();

    if (container && container->Extend3DContext() &&
        !container->UseIntermediateSurface()) {
      // Collect 3D layers in toSort array.
      container->Collect3DContextLeaves(toSort);

      // Sort the 3D layers.
      if (toSort.Length() > 0) {
        nsTArray<LayerPolygon> sorted = SortLayersWithBSPTree(toSort);
        drawOrder.AppendElements(std::move(sorted));

        toSort.ClearAndRetainStorage();
      }

      continue;
    }

    drawOrder.AppendElement(LayerPolygon(layer));
  }

  if (aSortMode == SortMode::WITHOUT_GEOMETRY) {
    // Compositor does not support arbitrary layers, strip the layer geometry
    // and duplicate layers.
    return StripLayerGeometry(drawOrder);
  }

  return drawOrder;
}

bool ContainerLayer::AnyAncestorOrThisIs3DContextLeaf() {
  Layer* parent = this;
  while (parent != nullptr) {
    if (parent->Is3DContextLeaf()) {
      return true;
    }

    parent = parent->GetParent();
  }

  return false;
}

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() || AnyAncestorOrThisIs3DContextLeaf()) &&
               Creates3DContextWithExtendingChildren()) {
      useIntermediateSurface = true;
    } else if (blendMode != CompositionOp::OP_OVER &&
               Manager()->BlendingRequiresIntermediateSurface()) {
      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;
  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;
}

// Note that ContainerLayer::RemoveAllChildren contains an optimized
// version of this code; if you make changes to ContainerLayer::DidRemoveChild
// consider whether the matching changes need to be made to
// ContainerLayer::RemoveAllChildren
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 RecordFrame, 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 FrameRecorder::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 FrameRecorder::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 FrameRecorder::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];
  }
}

static void PrintInfo(std::stringstream& aStream, HostLayer* 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, R"(array["%s"]=")",
                   string.BeginReading());
  }
  gfxUtils::DumpAsDataURI(aSurf, gfxUtils::sDumpPaintFile);
  if (gfxUtils::sDumpPaintFile != stderr) {
    fprintf_stderr(gfxUtils::sDumpPaintFile, R"(";)");
  }
}

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,
                 const Maybe<gfx::Polygon>& aGeometry) {
#ifdef MOZ_DUMP_PAINTING
  bool dumpCompositorTexture = gfxEnv::DumpCompositorTextures() &&
                               AsHostLayer() &&
                               AsHostLayer()->GetCompositableHost();
  bool dumpClientTexture = gfxEnv::DumpPaint() && AsShadowableLayer() &&
                           AsShadowableLayer()->GetCompositableClient();
  nsCString layerId(Name());
  layerId.Append('-');
  layerId.AppendInt((uint64_t)this);
#endif
  if (aDumpHtml) {
    aStream << nsPrintfCString(R"(<li><a id="%p" )", this).get();
#ifdef MOZ_DUMP_PAINTING
    if (dumpCompositorTexture || dumpClientTexture) {
      aStream << nsPrintfCString(R"lit(href="javascript:ViewImage('%s')")lit",
                                 layerId.BeginReading())
                     .get();
    }
#endif
    aStream << ">";
  }
  DumpSelf(aStream, aPrefix, aGeometry);

#ifdef MOZ_DUMP_PAINTING
  if (dumpCompositorTexture) {
    AsHostLayer()->GetCompositableHost()->Dump(aStream, aPrefix, aDumpHtml);
  } else if (dumpClientTexture) {
    if (aDumpHtml) {
      aStream << nsPrintfCString(R"(<script>array["%s"]=")",
                                 layerId.BeginReading())
                     .get();
    }
    AsShadowableLayer()->GetCompositableClient()->Dump(
        aStream, aPrefix, aDumpHtml, TextureDumpMode::DoNotCompress);
    if (aDumpHtml) {
      aStream << R"(";</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()) {
    nsTArray<LayerPolygon> children;
    if (aSorted) {
      children = container->SortChildrenBy3DZOrder(
          ContainerLayer::SortMode::WITH_GEOMETRY);
    } else {
      for (Layer* l = container->GetFirstChild(); l; l = l->GetNextSibling()) {
        children.AppendElement(LayerPolygon(l));
      }
    }
    nsAutoCString pfx(aPrefix);
    pfx += "  ";
    if (aDumpHtml) {
      aStream << "<ul>";
    }

    for (LayerPolygon& child : children) {
      child.layer->Dump(aStream, pfx.get(), aDumpHtml, aSorted, child.geometry);
    }

    if (aDumpHtml) {
      aStream << "</ul>";
    }
  }

  if (aDumpHtml) {
    aStream << "</li>";
  }
}

static void DumpGeometry(std::stringstream& aStream,
                         const Maybe<gfx::Polygon>& aGeometry) {
  aStream << " [geometry=[";

  const nsTArray<gfx::Point4D>& points = aGeometry->GetPoints();
  for (size_t i = 0; i < points.Length(); ++i) {
    const gfx::IntPoint point = TruncatedToInt(points[i].As2DPoint());
    const char* sfx = (i != points.Length() - 1) ? "," : "";
    AppendToString(aStream, point, "", sfx);
  }

  aStream << "]]";
}

void Layer::DumpSelf(std::stringstream& aStream, const char* aPrefix,
                     const Maybe<gfx::Polygon>& aGeometry) {
  PrintInfo(aStream, aPrefix);

  if (aGeometry) {
    DumpGeometry(aStream, aGeometry);
  }

  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 += R"(   \ 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, AsHostLayer());

  if (mClipRect) {
    AppendToString(aStream, *mClipRect, " [clip=", "]");
  }
  if (mSimpleAttrs.GetScrolledClip()) {
    AppendToString(aStream, mSimpleAttrs.GetScrolledClip()->GetClipRect(),
                   " [scrolled-clip=", "]");
    if (const Maybe<size_t>& ix =
            mSimpleAttrs.GetScrolledClip()->GetMaskLayerIndex()) {
      AppendToString(aStream, ix.value(), " [scrolled-mask=", "]");
    }
  }
  if (1.0 != mSimpleAttrs.GetPostXScale() ||
      1.0 != mSimpleAttrs.GetPostYScale()) {
    aStream << nsPrintfCString(" [postScale=%g, %g]",
                               mSimpleAttrs.GetPostXScale(),
                               mSimpleAttrs.GetPostYScale())
                   .get();
  }
  if (!GetBaseTransform().IsIdentity()) {
    AppendToString(aStream, GetBaseTransform(), " [transform=", "]");
  }
  if (!GetEffectiveTransform().IsIdentity()) {
    AppendToString(aStream, GetEffectiveTransform(),
                   " [effective-transform=", "]");
  }
  if (GetTransformIsPerspective()) {
    aStream << " [perspective]";
  }
  if (!mVisibleRegion.IsEmpty()) {
    AppendToString(aStream, mVisibleRegion.ToUnknownRegion(),
                   " [visible=", "]");
  } else {
    aStream << " [not visible]";
  }
  if (!mEventRegions.IsEmpty()) {
    AppendToString(aStream, mEventRegions, " ", "");
  }
  if (1.0 != GetOpacity()) {
    aStream << nsPrintfCString(" [opacity=%g]", GetOpacity()).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 (Maybe<FrameMetrics::ViewID> viewId = IsAsyncZoomContainer()) {
    aStream << nsPrintfCString(" [asyncZoomContainer scrollId=%" PRIu64 "]",
                               *viewId)
                   .get();
  }
  if (IsScrollbarContainer()) {
    aStream << " [scrollbar]";
  }
  if (GetScrollbarData().IsThumb()) {
    if (Maybe<ScrollDirection> thumbDirection = GetScrollbarData().mDirection) {
      if (*thumbDirection == ScrollDirection::eVertical) {
        aStream << nsPrintfCString(" [vscrollbar=%" PRIu64 "]",
                                   GetScrollbarData().mTargetViewId)
                       .get();
      }
      if (*thumbDirection == ScrollDirection::eHorizontal) {
        aStream << nsPrintfCString(" [hscrollbar=%" PRIu64 "]",
                                   GetScrollbarData().mTargetViewId)
                       .get();
      }
    }
  }
  if (GetIsFixedPosition()) {
    LayerPoint anchor = GetFixedPositionAnchor();
    aStream << nsPrintfCString(" [isFixedPosition scrollId=%" PRIu64
                               " sides=0x%x anchor=%s]",
                               GetFixedPositionScrollContainerId(),
                               GetFixedPositionSides(),
                               ToString(anchor).c_str())
                   .get();
  }
  if (GetIsStickyPosition()) {
    aStream << nsPrintfCString(" [isStickyPosition scrollId=%" PRIu64
                               " outer=(%.3f,%.3f)-(%.3f,%.3f) "
                               "inner=(%.3f,%.3f)-(%.3f,%.3f)]",
                               GetStickyScrollContainerId(),
                               GetStickyScrollRangeOuter().X(),
                               GetStickyScrollRangeOuter().Y(),
                               GetStickyScrollRangeOuter().XMost(),
                               GetStickyScrollRangeOuter().YMost(),
                               GetStickyScrollRangeInner().X(),
                               GetStickyScrollRangeInner().Y(),
                               GetStickyScrollRangeInner().XMost(),
                               GetStickyScrollRangeInner().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], "", "]");
    }
  }
  // FIXME: On the compositor thread, we don't set mAnimationInfo::mAnimations,
  // All animations are transformed by AnimationHelper::ExtractAnimations() into
  // mAnimationInfo.mPropertyAnimationGroups, instead. So if we want to check
  // if layer trees are properly synced up across processes, we should dump
  // mAnimationInfo.mPropertyAnimationGroups for the compositor thread.
  // (See AnimationInfo.h for more details.)
  if (!mAnimationInfo.GetAnimations().IsEmpty()) {
    aStream << nsPrintfCString(" [%d animations with id=%" PRIu64 " ]",
                               (int)mAnimationInfo.GetAnimations().Length(),
                               mAnimationInfo.GetCompositorAnimationsId())
                   .get();
  }
}

// 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 (HostLayer* lc = AsHostLayer()) {
    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 (!GetBaseTransform().IsIdentity()) {
    DumpTransform(layer->mutable_transform(), GetBaseTransform());
  }
  // 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(GetOpacity());
  // 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 (GetScrollbarData().mScrollbarLayerType ==
      layers::ScrollbarLayerType::Thumb) {
    layer->set_direct(*GetScrollbarData().mDirection ==
                              ScrollDirection::eVertical
                          ? LayersPacket::Layer::VERTICAL
                          : LayersPacket::Layer::HORIZONTAL);
    layer->set_barid(GetScrollbarData().mTargetViewId);
  }

  // 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 Layer::SetManager(LayerManager* aManager, HostLayer* aSelf) {
  // No one should be calling this for weird reasons.
  MOZ_ASSERT(aSelf);
  MOZ_ASSERT(aSelf->GetLayer() == this);
  mManager = aManager;
}

void PaintedLayer::PrintInfo(std::stringstream& aStream, const char* aPrefix) {
  Layer::PrintInfo(aStream, aPrefix);
  nsIntRegion validRegion = GetValidRegion();
  if (!validRegion.IsEmpty()) {
    AppendToString(aStream, validRegion, " [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);
  nsIntRegion validRegion = GetValidRegion();
  if (!validRegion.IsEmpty()) {
    DumpRegion(layer->mutable_valid(), validRegion);
  }
}

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();
  }
  aStream << nsPrintfCString(" [presShellResolution=%g]", mPresShellResolution)
                 .get();
}

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), mSamplingFilter(SamplingFilter::GOOD) {}

CanvasLayer::~CanvasLayer() = default;

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);
}

CanvasRenderer* CanvasLayer::CreateOrGetCanvasRenderer() {
  if (!mCanvasRenderer) {
    mCanvasRenderer.reset(CreateCanvasRendererInternal());
  }

  return mCanvasRenderer.get();
}

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 (mId.IsValid()) {
    AppendToString(aStream, uint64_t(mId), " [id=", "]");
  }
  if (mEventRegionsOverride & EventRegionsOverride::ForceDispatchToContent) {
    aStream << " [force-dtc]";
  }
  if (mEventRegionsOverride & EventRegionsOverride::ForceEmptyHitRegion) {
    aStream << " [force-ehr]";
  }
}

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(uint64_t(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)\n", pfx.get()).get();
    if (aDumpHtml) {
      aStream << "</li></ul>";
    }
    return;
  }

  if (aDumpHtml) {
    aStream << "<ul>";
  }
  GetRoot()->Dump(aStream, pfx.get(), aDumpHtml, aSorted);
  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);
}

bool LayerManager::SetPendingScrollUpdateForNextTransaction(
    ScrollableLayerGuid::ViewID aScrollId,
    const ScrollUpdateInfo& aUpdateInfo) {
  Layer* withPendingTransform = DepthFirstSearch<ForwardIterator>(
      GetRoot(), [](Layer* aLayer) { return aLayer->HasPendingTransform(); });
  if (withPendingTransform) {
    return false;
  }

  mPendingScrollUpdates[aScrollId] = aUpdateInfo;
  return true;
}

Maybe<ScrollUpdateInfo> LayerManager::GetPendingScrollInfoUpdate(
    ScrollableLayerGuid::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, HostLayer* 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().GetBounds().ToUnknownRect();
  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