Make 2D canvas smarter about chosing whether or not to use GPU acceleration

third_party/WebKit/Source/platform/graphics/Canvas2DImageBufferSurface.h

Index: third_party/WebKit/Source/platform/graphics/Canvas2DImageBufferSurface.h
diff --git a/third_party/WebKit/Source/platform/graphics/Canvas2DImageBufferSurface.h b/third_party/WebKit/Source/platform/graphics/Canvas2DImageBufferSurface.h
index e1d2414c2d215ac8ad09376a6d453ae37c5f5f78..b215d35575939f2697ac03b6c679f76b04f45e13 100644
--- a/third_party/WebKit/Source/platform/graphics/Canvas2DImageBufferSurface.h
+++ b/third_party/WebKit/Source/platform/graphics/Canvas2DImageBufferSurface.h
@@ -39,9 +39,9 @@ namespace blink {
 // This shim necessary because ImageBufferSurfaces are not allowed to be RefCounted
 class Canvas2DImageBufferSurface final : public ImageBufferSurface {
 public:
-    Canvas2DImageBufferSurface(const IntSize& size, OpacityMode opacityMode = NonOpaque, int msaaSampleCount = 1)
+    Canvas2DImageBufferSurface(const IntSize& size, int msaaSampleCount, OpacityMode opacityMode, Canvas2DLayerBridge::AccelerationMode accelerationMode)
         : ImageBufferSurface(size, opacityMode)
-        , m_layerBridge(Canvas2DLayerBridge::create(size, opacityMode, msaaSampleCount))
+        , m_layerBridge(Canvas2DLayerBridge::create(size, msaaSampleCount, opacityMode, accelerationMode))
     {
         clear();
         if (isValid())
@@ -69,9 +69,10 @@ public:
     void didDraw(const FloatRect& rect) override { m_layerBridge->didDraw(rect); }
     void flush() override { m_layerBridge->flush(); }
     void flushGpu() override { m_layerBridge->flushGpu(); }
+    void prepareSurfaceForPaintingIfNeeded() override { m_layerBridge->prepareSurfaceForPaintingIfNeeded(); }
     bool writePixels(const SkImageInfo& origInfo, const void* pixels, size_t rowBytes, int x, int y) override { return m_layerBridge->writePixels(origInfo, pixels, rowBytes, x, y); }
 
-    PassRefPtr<SkImage> newImageSnapshot() override { return m_layerBridge->newImageSnapshot(); }
+    PassRefPtr<SkImage> newImageSnapshot(AccelerationHint hint) override { return m_layerBridge->newImageSnapshot(hint); }
 private:
     RefPtr<Canvas2DLayerBridge> m_layerBridge;
 };