C++ TiledLayerComposer类代码示例

static void
DispatchMemoryPressureToLayers(Layer* aLayer)
{
  ShadowLayer* shadowLayer = aLayer->AsShadowLayer();
  if (shadowLayer) {
    TiledLayerComposer* tileComposer = shadowLayer->AsTiledLayerComposer();
    if (tileComposer) {
      tileComposer->MemoryPressure();
    }
  }

  for (Layer* child = aLayer->GetFirstChild();
         child; child = child->GetNextSibling()) {
    DispatchMemoryPressureToLayers(child);
  }

}

bool
CompositableParentManager::ReceiveCompositableUpdate(const CompositableOperation& aEdit,
                                                     EditReplyVector& replyv)
{
  switch (aEdit.type()) {
    case CompositableOperation::TOpCreatedIncrementalTexture: {
      MOZ_LAYERS_LOG(("[ParentSide] Created texture"));
      const OpCreatedIncrementalTexture& op = aEdit.get_OpCreatedIncrementalTexture();
      CompositableHost* compositable = AsCompositable(op);

      bool success =
        compositable->CreatedIncrementalTexture(this,
                                                op.textureInfo(),
                                                op.bufferRect());
      if (!success) {
        return false;
      }
      break;
    }
    case CompositableOperation::TOpPaintTextureRegion: {
      MOZ_LAYERS_LOG(("[ParentSide] Paint ThebesLayer"));

      const OpPaintTextureRegion& op = aEdit.get_OpPaintTextureRegion();
      CompositableHost* compositable = AsCompositable(op);
      Layer* layer = compositable->GetLayer();
      if (!layer || layer->GetType() != Layer::TYPE_THEBES) {
        return false;
      }
      ThebesLayerComposite* thebes = static_cast<ThebesLayerComposite*>(layer);

      const ThebesBufferData& bufferData = op.bufferData();

      RenderTraceInvalidateStart(thebes, "FF00FF", op.updatedRegion().GetBounds());

      nsIntRegion frontUpdatedRegion;
      if (!compositable->UpdateThebes(bufferData,
                                      op.updatedRegion(),
                                      thebes->GetValidRegion(),
                                      &frontUpdatedRegion))
      {
        return false;
      }
      replyv.push_back(
        OpContentBufferSwap(op.compositableParent(), nullptr, frontUpdatedRegion));

      RenderTraceInvalidateEnd(thebes, "FF00FF");
      break;
    }
    case CompositableOperation::TOpPaintTextureIncremental: {
      MOZ_LAYERS_LOG(("[ParentSide] Paint ThebesLayer"));

      const OpPaintTextureIncremental& op = aEdit.get_OpPaintTextureIncremental();

      CompositableHost* compositable = AsCompositable(op);

      SurfaceDescriptor desc = op.image();

      compositable->UpdateIncremental(op.textureId(),
                                      desc,
                                      op.updatedRegion(),
                                      op.bufferRect(),
                                      op.bufferRotation());
      break;
    }
    case CompositableOperation::TOpUpdatePictureRect: {
      const OpUpdatePictureRect& op = aEdit.get_OpUpdatePictureRect();
      CompositableHost* compositable = AsCompositable(op);
      MOZ_ASSERT(compositable);
      compositable->SetPictureRect(op.picture());
      break;
    }
    case CompositableOperation::TOpUseTiledLayerBuffer: {
      MOZ_LAYERS_LOG(("[ParentSide] Paint TiledLayerBuffer"));
      const OpUseTiledLayerBuffer& op = aEdit.get_OpUseTiledLayerBuffer();
      CompositableHost* compositable = AsCompositable(op);

      TiledLayerComposer* tileComposer = compositable->AsTiledLayerComposer();
      NS_ASSERTION(tileComposer, "compositable is not a tile composer");

      const SurfaceDescriptorTiles& tileDesc = op.tileLayerDescriptor();
      tileComposer->UseTiledLayerBuffer(this, tileDesc);
      break;
    }
    case CompositableOperation::TOpRemoveTexture: {
      const OpRemoveTexture& op = aEdit.get_OpRemoveTexture();
      CompositableHost* compositable = AsCompositable(op);
      RefPtr<TextureHost> tex = TextureHost::AsTextureHost(op.textureParent());

      MOZ_ASSERT(tex.get());
      compositable->RemoveTextureHost(tex);
      // send FenceHandle if present.
      TextureHost::SendFenceHandleIfPresent(op.textureParent());
      break;
    }
    case CompositableOperation::TOpRemoveTextureAsync: {
      const OpRemoveTextureAsync& op = aEdit.get_OpRemoveTextureAsync();
      CompositableHost* compositable = AsCompositable(op);
      RefPtr<TextureHost> tex = TextureHost::AsTextureHost(op.textureParent());

      MOZ_ASSERT(tex.get());
//.........这里部分代码省略.........

//.........这里部分代码省略.........
      break;
    }
    case Edit::TOpRemoveChild: {
      MOZ_LAYERS_LOG(("[ParentSide] RemoveChild"));

      const OpRemoveChild& orc = edit.get_OpRemoveChild();
      Layer* childLayer = ShadowChild(orc)->AsLayer();
      ShadowContainer(orc)->AsContainer()->RemoveChild(childLayer);
      break;
    }
    case Edit::TOpRepositionChild: {
      MOZ_LAYERS_LOG(("[ParentSide] RepositionChild"));

      const OpRepositionChild& orc = edit.get_OpRepositionChild();
      ShadowContainer(orc)->AsContainer()->RepositionChild(
        ShadowChild(orc)->AsLayer(), ShadowAfter(orc)->AsLayer());
      break;
    }
    case Edit::TOpRaiseToTopChild: {
      MOZ_LAYERS_LOG(("[ParentSide] RaiseToTopChild"));

      const OpRaiseToTopChild& rtc = edit.get_OpRaiseToTopChild();
      ShadowContainer(rtc)->AsContainer()->RepositionChild(
        ShadowChild(rtc)->AsLayer(), NULL);
      break;
    }

    case Edit::TOpPaintTiledLayerBuffer: {
      MOZ_LAYERS_LOG(("[ParentSide] Paint TiledLayerBuffer"));
      const OpPaintTiledLayerBuffer& op = edit.get_OpPaintTiledLayerBuffer();
      ShadowLayerParent* shadow = AsShadowLayer(op);

      ShadowThebesLayer* shadowLayer = static_cast<ShadowThebesLayer*>(shadow->AsLayer());
      TiledLayerComposer* tileComposer = shadowLayer->AsTiledLayerComposer();

      NS_ASSERTION(tileComposer, "shadowLayer is not a tile composer");

      BasicTiledLayerBuffer* p = (BasicTiledLayerBuffer*)op.tiledLayerBuffer();
      tileComposer->PaintedTiledLayerBuffer(p);
      break;
    }
    case Edit::TOpPaintThebesBuffer: {
      MOZ_LAYERS_LOG(("[ParentSide] Paint ThebesLayer"));

      const OpPaintThebesBuffer& op = edit.get_OpPaintThebesBuffer();
      ShadowLayerParent* shadow = AsShadowLayer(op);
      ShadowThebesLayer* thebes =
        static_cast<ShadowThebesLayer*>(shadow->AsLayer());
      const ThebesBuffer& newFront = op.newFrontBuffer();

      RenderTraceInvalidateStart(thebes, "FF00FF", op.updatedRegion().GetBounds());

      OptionalThebesBuffer newBack;
      nsIntRegion newValidRegion;
      OptionalThebesBuffer readonlyFront;
      nsIntRegion frontUpdatedRegion;
      thebes->Swap(newFront, op.updatedRegion(),
                   &newBack, &newValidRegion,
                   &readonlyFront, &frontUpdatedRegion);
      replyv.push_back(
        OpThebesBufferSwap(
          shadow, NULL,
          newBack, newValidRegion,
          readonlyFront, frontUpdatedRegion));

      RenderTraceInvalidateEnd(thebes, "FF00FF");

//.........这里部分代码省略.........
    case CompositableOperation::TOpPaintTextureIncremental: {
      MOZ_LAYERS_LOG(("[ParentSide] Paint ThebesLayer"));

      const OpPaintTextureIncremental& op = aEdit.get_OpPaintTextureIncremental();

      CompositableParent* compositableParent = static_cast<CompositableParent*>(op.compositableParent());
      CompositableHost* compositable =
        compositableParent->GetCompositableHost();

      SurfaceDescriptor desc = op.image();

      compositable->UpdateIncremental(op.textureId(),
                                      desc,
                                      op.updatedRegion(),
                                      op.bufferRect(),
                                      op.bufferRotation());
      break;
    }
    case CompositableOperation::TOpUpdatePictureRect: {
      const OpUpdatePictureRect& op = aEdit.get_OpUpdatePictureRect();
      CompositableHost* compositable
       = static_cast<CompositableParent*>(op.compositableParent())->GetCompositableHost();
      MOZ_ASSERT(compositable);
      compositable->SetPictureRect(op.picture());
      break;
    }
    case CompositableOperation::TOpUseTiledLayerBuffer: {
      MOZ_LAYERS_LOG(("[ParentSide] Paint TiledLayerBuffer"));
      const OpUseTiledLayerBuffer& op = aEdit.get_OpUseTiledLayerBuffer();
      CompositableParent* compositableParent = static_cast<CompositableParent*>(op.compositableParent());
      CompositableHost* compositable =
        compositableParent->GetCompositableHost();

      TiledLayerComposer* tileComposer = compositable->AsTiledLayerComposer();
      NS_ASSERTION(tileComposer, "compositable is not a tile composer");

      const SurfaceDescriptorTiles& tileDesc = op.tileLayerDescriptor();
      tileComposer->UseTiledLayerBuffer(this, tileDesc);
      break;
    }
    case CompositableOperation::TOpRemoveTexture: {
      const OpRemoveTexture& op = aEdit.get_OpRemoveTexture();
      CompositableHost* compositable = AsCompositable(op);
      RefPtr<TextureHost> tex = TextureHost::AsTextureHost(op.textureParent());

      MOZ_ASSERT(tex.get());
      compositable->RemoveTextureHost(tex);
      // return texure data to client if necessary
      ReturnTextureDataIfNecessary(compositable, replyv, op.compositableParent());
      break;
    }
    case CompositableOperation::TOpUseTexture: {
      const OpUseTexture& op = aEdit.get_OpUseTexture();
      CompositableHost* compositable = AsCompositable(op);
      RefPtr<TextureHost> tex = TextureHost::AsTextureHost(op.textureParent());

      MOZ_ASSERT(tex.get());
      compositable->UseTextureHost(tex);

      if (IsAsync()) {
        ScheduleComposition(op);
        // Async layer updates don't trigger invalidation, manually tell the layer
        // that its content have changed.
        if (compositable->GetLayer()) {
          compositable->GetLayer()->SetInvalidRectToVisibleRegion();
        }

bool
CompositableParentManager::ReceiveCompositableUpdate(const CompositableOperation& aEdit,
                                                     EditReplyVector& replyv)
{
  switch (aEdit.type()) {
    case CompositableOperation::TOpCreatedIncrementalTexture: {
      MOZ_LAYERS_LOG(("[ParentSide] Created texture"));
      const OpCreatedIncrementalTexture& op = aEdit.get_OpCreatedIncrementalTexture();
      CompositableHost* compositable = AsCompositable(op);

      bool success =
        compositable->CreatedIncrementalTexture(this,
                                                op.textureInfo(),
                                                op.bufferRect());
      if (!success) {
        return false;
      }
      break;
    }
    case CompositableOperation::TOpPaintTextureRegion: {
      MOZ_LAYERS_LOG(("[ParentSide] Paint ThebesLayer"));

      const OpPaintTextureRegion& op = aEdit.get_OpPaintTextureRegion();
      CompositableHost* compositable = AsCompositable(op);
      Layer* layer = compositable->GetLayer();
      if (!layer || layer->GetType() != Layer::TYPE_THEBES) {
        return false;
      }
      ThebesLayerComposite* thebes = static_cast<ThebesLayerComposite*>(layer);

      const ThebesBufferData& bufferData = op.bufferData();

      RenderTraceInvalidateStart(thebes, "FF00FF", op.updatedRegion().GetBounds());

      nsIntRegion frontUpdatedRegion;
      if (!compositable->UpdateThebes(bufferData,
                                      op.updatedRegion(),
                                      thebes->GetValidRegion(),
                                      &frontUpdatedRegion))
      {
        return false;
      }
      replyv.push_back(
        OpContentBufferSwap(op.compositableParent(), nullptr, frontUpdatedRegion));

      RenderTraceInvalidateEnd(thebes, "FF00FF");
      // return texure data to client if necessary
      ReturnTextureDataIfNecessary(compositable, replyv, op.compositableParent());
      break;
    }
    case CompositableOperation::TOpPaintTextureIncremental: {
      MOZ_LAYERS_LOG(("[ParentSide] Paint ThebesLayer"));

      const OpPaintTextureIncremental& op = aEdit.get_OpPaintTextureIncremental();

      CompositableHost* compositable = AsCompositable(op);

      SurfaceDescriptor desc = op.image();

      compositable->UpdateIncremental(op.textureId(),
                                      desc,
                                      op.updatedRegion(),
                                      op.bufferRect(),
                                      op.bufferRotation());
      break;
    }
    case CompositableOperation::TOpUpdatePictureRect: {
      const OpUpdatePictureRect& op = aEdit.get_OpUpdatePictureRect();
      CompositableHost* compositable = AsCompositable(op);
      MOZ_ASSERT(compositable);
      compositable->SetPictureRect(op.picture());
      break;
    }
    case CompositableOperation::TOpUseTiledLayerBuffer: {
      MOZ_LAYERS_LOG(("[ParentSide] Paint TiledLayerBuffer"));
      const OpUseTiledLayerBuffer& op = aEdit.get_OpUseTiledLayerBuffer();
      CompositableHost* compositable = AsCompositable(op);

      TiledLayerComposer* tileComposer = compositable->AsTiledLayerComposer();
      NS_ASSERTION(tileComposer, "compositable is not a tile composer");

      const SurfaceDescriptorTiles& tileDesc = op.tileLayerDescriptor();
      tileComposer->UseTiledLayerBuffer(this, tileDesc);
      break;
    }
    case CompositableOperation::TOpRemoveTexture: {
      const OpRemoveTexture& op = aEdit.get_OpRemoveTexture();
      CompositableHost* compositable = AsCompositable(op);
      RefPtr<TextureHost> tex = TextureHost::AsTextureHost(op.textureParent());

      MOZ_ASSERT(tex.get());
      compositable->RemoveTextureHost(tex);
      // return texure data to client if necessary
      ReturnTextureDataIfNecessary(compositable, replyv, op.compositableParent());
      break;
    }
    case CompositableOperation::TOpUseTexture: {
      const OpUseTexture& op = aEdit.get_OpUseTexture();
      CompositableHost* compositable = AsCompositable(op);
      RefPtr<TextureHost> tex = TextureHost::AsTextureHost(op.textureParent());
//.........这里部分代码省略.........

/* static */ void
LayerManagerComposite::ComputeRenderIntegrityInternal(Layer* aLayer,
                                                      nsIntRegion& aScreenRegion,
                                                      nsIntRegion& aLowPrecisionScreenRegion,
                                                      const Matrix4x4& aTransform)
{
  if (aLayer->GetOpacity() <= 0.f ||
      (aScreenRegion.IsEmpty() && aLowPrecisionScreenRegion.IsEmpty())) {
    return;
  }

  // If the layer's a container, recurse into all of its children
  ContainerLayer* container = aLayer->AsContainerLayer();
  if (container) {
    // Accumulate the transform of intermediate surfaces
    Matrix4x4 transform = aTransform;
    if (container->UseIntermediateSurface()) {
      transform = aLayer->GetEffectiveTransform();
      transform = aTransform * transform;
    }
    for (Layer* child = aLayer->GetFirstChild(); child;
         child = child->GetNextSibling()) {
      ComputeRenderIntegrityInternal(child, aScreenRegion, aLowPrecisionScreenRegion, transform);
    }
    return;
  }

  // Only thebes layers can be incomplete
  ThebesLayer* thebesLayer = aLayer->AsThebesLayer();
  if (!thebesLayer) {
    return;
  }

  // See if there's any incomplete rendering
  nsIntRegion incompleteRegion = aLayer->GetEffectiveVisibleRegion();
  incompleteRegion.Sub(incompleteRegion, thebesLayer->GetValidRegion());

  if (!incompleteRegion.IsEmpty()) {
    // Calculate the transform to get between screen and layer space
    Matrix4x4 transformToScreen = aLayer->GetEffectiveTransform();
    transformToScreen = aTransform * transformToScreen;

    SubtractTransformedRegion(aScreenRegion, incompleteRegion, transformToScreen);

    // See if there's any incomplete low-precision rendering
    TiledLayerComposer* composer = nullptr;
    LayerComposite* shadow = aLayer->AsLayerComposite();
    if (shadow) {
      composer = shadow->GetTiledLayerComposer();
      if (composer) {
        incompleteRegion.Sub(incompleteRegion, composer->GetValidLowPrecisionRegion());
        if (!incompleteRegion.IsEmpty()) {
          SubtractTransformedRegion(aLowPrecisionScreenRegion, incompleteRegion, transformToScreen);
        }
      }
    }

    // If we can't get a valid low precision region, assume it's the same as
    // the high precision region.
    if (!composer) {
      SubtractTransformedRegion(aLowPrecisionScreenRegion, incompleteRegion, transformToScreen);
    }
  }
}

//.........这里部分代码省略.........
      LayerComposite* shadowLayer = layer ? layer->AsLayerComposite() : nullptr;
      if (shadowLayer) {
        Compositor* compositor = static_cast<LayerManagerComposite*>(layer->Manager())->GetCompositor();
        compositable->SetCompositor(compositor);
        compositable->SetLayer(layer);
      } else {
        // if we reach this branch, it most likely means that async textures
        // are coming in before we had time to attach the conmpositable to a
        // layer. Don't panic, it is okay in this case. it should not be
        // happening continuously, though.
      }

      if (layer) {
        RenderTraceInvalidateStart(layer, "FF00FF", layer->GetVisibleRegion().GetBounds());
      }

      if (compositable) {
        const SurfaceDescriptor& descriptor = op.image();
        compositable->EnsureTextureHost(op.textureId(),
                                        descriptor,
                                        compositableParent->GetCompositableManager(),
                                        TextureInfo());
        MOZ_ASSERT(compositable->GetTextureHost());

        SurfaceDescriptor newBack;
        bool shouldRecomposite = compositable->Update(descriptor, &newBack);
        if (IsSurfaceDescriptorValid(newBack)) {
          replyv.push_back(OpTextureSwap(compositableParent, nullptr,
                                         op.textureId(), newBack));
        }

        if (shouldRecomposite && compositableParent->GetCompositorID()) {
          CompositorParent* cp
            = CompositorParent::GetCompositor(compositableParent->GetCompositorID());
          if (cp) {
            cp->ScheduleComposition();
          }
        }
      }

      if (layer) {
        RenderTraceInvalidateEnd(layer, "FF00FF");
      }

      break;
    }
    case CompositableOperation::TOpPaintTextureRegion: {
      MOZ_LAYERS_LOG(("[ParentSide] Paint ThebesLayer"));

      const OpPaintTextureRegion& op = aEdit.get_OpPaintTextureRegion();
      CompositableParent* compositableParent = static_cast<CompositableParent*>(op.compositableParent());
      CompositableHost* compositable =
        compositableParent->GetCompositableHost();
      ThebesLayerComposite* thebes =
        static_cast<ThebesLayerComposite*>(compositable->GetLayer());

      const ThebesBufferData& bufferData = op.bufferData();

      RenderTraceInvalidateStart(thebes, "FF00FF", op.updatedRegion().GetBounds());

      nsIntRegion frontUpdatedRegion;
      compositable->UpdateThebes(bufferData,
                                 op.updatedRegion(),
                                 thebes->GetValidRegion(),
                                 &frontUpdatedRegion);
      replyv.push_back(
        OpContentBufferSwap(compositableParent, nullptr, frontUpdatedRegion));

      RenderTraceInvalidateEnd(thebes, "FF00FF");
      break;
    }
    case CompositableOperation::TOpUpdatePictureRect: {
      const OpUpdatePictureRect& op = aEdit.get_OpUpdatePictureRect();
      CompositableHost* compositable
       = static_cast<CompositableParent*>(op.compositableParent())->GetCompositableHost();
      MOZ_ASSERT(compositable);
      compositable->SetPictureRect(op.picture());
      break;
    }
    case CompositableOperation::TOpPaintTiledLayerBuffer: {
      MOZ_LAYERS_LOG(("[ParentSide] Paint TiledLayerBuffer"));
      const OpPaintTiledLayerBuffer& op = aEdit.get_OpPaintTiledLayerBuffer();
      CompositableParent* compositableParent = static_cast<CompositableParent*>(op.compositableParent());
      CompositableHost* compositable =
        compositableParent->GetCompositableHost();

      TiledLayerComposer* tileComposer = compositable->AsTiledLayerComposer();
      NS_ASSERTION(tileComposer, "compositable is not a tile composer");

      BasicTiledLayerBuffer* p = reinterpret_cast<BasicTiledLayerBuffer*>(op.tiledLayerBuffer());
      tileComposer->PaintedTiledLayerBuffer(p);
      break;
    }
    default: {
      MOZ_ASSERT(false, "bad type");
    }
  }

  return true;
}

//.........这里部分代码省略.........
      const OpInsertAfter& oia = edit.get_OpInsertAfter();
      ShadowContainer(oia)->AsContainer()->InsertAfter(
        ShadowChild(oia)->AsLayer(), ShadowAfter(oia)->AsLayer());
      break;
    }
    case Edit::TOpAppendChild: {
      MOZ_LAYERS_LOG(("[ParentSide] AppendChild"));

      const OpAppendChild& oac = edit.get_OpAppendChild();
      ShadowContainer(oac)->AsContainer()->InsertAfter(
        ShadowChild(oac)->AsLayer(), NULL);
      break;
    }
    case Edit::TOpRemoveChild: {
      MOZ_LAYERS_LOG(("[ParentSide] RemoveChild"));

      const OpRemoveChild& orc = edit.get_OpRemoveChild();
      Layer* childLayer = ShadowChild(orc)->AsLayer();
      ShadowContainer(orc)->AsContainer()->RemoveChild(childLayer);
      break;
    }
    case Edit::TOpRepositionChild: {
      MOZ_LAYERS_LOG(("[ParentSide] RepositionChild"));

      const OpRepositionChild& orc = edit.get_OpRepositionChild();
      ShadowContainer(orc)->AsContainer()->RepositionChild(
        ShadowChild(orc)->AsLayer(), ShadowAfter(orc)->AsLayer());
      break;
    }
    case Edit::TOpRaiseToTopChild: {
      MOZ_LAYERS_LOG(("[ParentSide] RaiseToTopChild"));

      const OpRaiseToTopChild& rtc = edit.get_OpRaiseToTopChild();
      ShadowContainer(rtc)->AsContainer()->RepositionChild(
        ShadowChild(rtc)->AsLayer(), NULL);
      break;
    }
    case Edit::TCompositableOperation: {
      ReceiveCompositableUpdate(edit.get_CompositableOperation(),
                                replyv);
      break;
    }
    case Edit::TOpAttachCompositable: {
      const OpAttachCompositable& op = edit.get_OpAttachCompositable();
      Attach(cast(op.layerParent()), cast(op.compositableParent()));
      break;
    }
    case Edit::TOpAttachAsyncCompositable: {
      const OpAttachAsyncCompositable& op = edit.get_OpAttachAsyncCompositable();
      CompositableParent* compositableParent = CompositableMap::Get(op.containerID());
      MOZ_ASSERT(compositableParent, "CompositableParent not found in the map");
      Attach(cast(op.layerParent()), compositableParent);
      compositableParent->SetCompositorID(mLayerManager->GetCompositor()->GetCompositorID());
      break;
    }
    case Edit::TOpPaintTiledLayerBuffer: {
      MOZ_LAYERS_LOG(("[ParentSide] Paint TiledLayerBuffer"));
      const OpPaintTiledLayerBuffer& op = edit.get_OpPaintTiledLayerBuffer();
      ShadowLayerParent* shadow = AsShadowLayer(op);

      LayerComposite* compositeLayer = shadow->AsLayer()->AsLayerComposite();
      compositeLayer->EnsureBuffer(BUFFER_TILED);
      TiledLayerComposer* tileComposer = compositeLayer->AsTiledLayerComposer();

      NS_ASSERTION(tileComposer, "compositeLayer is not a tile composer");

      BasicTiledLayerBuffer* p = reinterpret_cast<BasicTiledLayerBuffer*>(op.tiledLayerBuffer());
      tileComposer->PaintedTiledLayerBuffer(p);
      break;
    }
    default:
      NS_RUNTIMEABORT("not reached");
    }
  }

  layer_manager()->EndTransaction(NULL, NULL, LayerManager::END_NO_IMMEDIATE_REDRAW);

  if (reply) {
    reply->SetCapacity(replyv.size());
    if (replyv.size() > 0) {
      reply->AppendElements(&replyv.front(), replyv.size());
    }
  }

  // Ensure that any pending operations involving back and front
  // buffers have completed, so that neither process stomps on the
  // other's buffer contents.
  ShadowLayerManager::PlatformSyncBeforeReplyUpdate();

  mShadowLayersManager->ShadowLayersUpdated(this, targetConfig, isFirstPaint);

#ifdef COMPOSITOR_PERFORMANCE_WARNING
  int compositeTime = (int)(mozilla::TimeStamp::Now() - updateStart).ToMilliseconds();
  if (compositeTime > 15) {
    printf_stderr("Compositor: Layers update took %i ms (blocking gecko).\n", compositeTime);
  }
#endif

  return true;
}