diff -r 000000000000 -r 6474c204b198 gfx/layers/composite/CanvasLayerComposite.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/layers/composite/CanvasLayerComposite.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,145 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "CanvasLayerComposite.h"
+#include "composite/CompositableHost.h"  // for CompositableHost
+#include "gfx2DGlue.h"                  // for ToFilter, ToMatrix4x4
+#include "GraphicsFilter.h"             // for GraphicsFilter
+#include "gfxUtils.h"                   // for gfxUtils, etc
+#include "mozilla/gfx/Matrix.h"         // for Matrix4x4
+#include "mozilla/gfx/Point.h"          // for Point
+#include "mozilla/gfx/Rect.h"           // for Rect
+#include "mozilla/layers/Compositor.h"  // for Compositor
+#include "mozilla/layers/Effects.h"     // for EffectChain
+#include "mozilla/mozalloc.h"           // for operator delete
+#include "nsAString.h"
+#include "nsAutoPtr.h"                  // for nsRefPtr
+#include "nsISupportsImpl.h"            // for MOZ_COUNT_CTOR, etc
+#include "nsPoint.h"                    // for nsIntPoint
+#include "nsString.h"                   // for nsAutoCString
+
+using namespace mozilla;
+using namespace mozilla::layers;
+using namespace mozilla::gfx;
+
+CanvasLayerComposite::CanvasLayerComposite(LayerManagerComposite* aManager)
+  : CanvasLayer(aManager, nullptr)
+  , LayerComposite(aManager)
+  , mImageHost(nullptr)
+{
+  MOZ_COUNT_CTOR(CanvasLayerComposite);
+  mImplData = static_cast<LayerComposite*>(this);
+}
+
+CanvasLayerComposite::~CanvasLayerComposite()
+{
+  MOZ_COUNT_DTOR(CanvasLayerComposite);
+
+  CleanupResources();
+}
+
+bool
+CanvasLayerComposite::SetCompositableHost(CompositableHost* aHost)
+{
+  switch (aHost->GetType()) {
+    case BUFFER_IMAGE_SINGLE:
+    case BUFFER_IMAGE_BUFFERED:
+    case COMPOSITABLE_IMAGE:
+      mImageHost = aHost;
+      return true;
+    default:
+      return false;
+  }
+
+}
+
+Layer*
+CanvasLayerComposite::GetLayer()
+{
+  return this;
+}
+
+LayerRenderState
+CanvasLayerComposite::GetRenderState()
+{
+  if (mDestroyed || !mImageHost || !mImageHost->IsAttached()) {
+    return LayerRenderState();
+  }
+  return mImageHost->GetRenderState();
+}
+
+void
+CanvasLayerComposite::RenderLayer(const nsIntRect& aClipRect)
+{
+  if (!mImageHost || !mImageHost->IsAttached()) {
+    return;
+  }
+
+  mCompositor->MakeCurrent();
+
+#ifdef MOZ_DUMP_PAINTING
+  if (gfxUtils::sDumpPainting) {
+    RefPtr<gfx::DataSourceSurface> surf = mImageHost->GetAsSurface();
+    WriteSnapshotToDumpFile(this, surf);
+  }
+#endif
+
+  GraphicsFilter filter = mFilter;
+#ifdef ANDROID
+  // Bug 691354
+  // Using the LINEAR filter we get unexplained artifacts.
+  // Use NEAREST when no scaling is required.
+  Matrix matrix;
+  bool is2D = GetEffectiveTransform().Is2D(&matrix);
+  if (is2D && !ThebesMatrix(matrix).HasNonTranslationOrFlip()) {
+    filter = GraphicsFilter::FILTER_NEAREST;
+  }
+#endif
+
+  EffectChain effectChain(this);
+
+  LayerManagerComposite::AutoAddMaskEffect autoMaskEffect(mMaskLayer, effectChain);
+  gfx::Rect clipRect(aClipRect.x, aClipRect.y, aClipRect.width, aClipRect.height);
+
+  mImageHost->Composite(effectChain,
+                        GetEffectiveOpacity(),
+                        GetEffectiveTransform(),
+                        gfx::ToFilter(filter),
+                        clipRect);
+  mImageHost->BumpFlashCounter();
+}
+
+CompositableHost*
+CanvasLayerComposite::GetCompositableHost()
+{
+  if ( mImageHost && mImageHost->IsAttached()) {
+    return mImageHost.get();
+  }
+
+  return nullptr;
+}
+
+void
+CanvasLayerComposite::CleanupResources()
+{
+  if (mImageHost) {
+    mImageHost->Detach(this);
+  }
+  mImageHost = nullptr;
+}
+
+nsACString&
+CanvasLayerComposite::PrintInfo(nsACString& aTo, const char* aPrefix)
+{
+  CanvasLayer::PrintInfo(aTo, aPrefix);
+  aTo += "\n";
+  if (mImageHost && mImageHost->IsAttached()) {
+    nsAutoCString pfx(aPrefix);
+    pfx += "  ";
+    mImageHost->PrintInfo(aTo, pfx.get());
+  }
+  return aTo;
+}
+