Add CanvasSurfaceLayerBridge

third_party/WebKit/Source/core/html/HTMLCanvasElement.h

Index: third_party/WebKit/Source/core/html/HTMLCanvasElement.h
diff --git a/third_party/WebKit/Source/core/html/HTMLCanvasElement.h b/third_party/WebKit/Source/core/html/HTMLCanvasElement.h
index 8c23e4dcb1f07baa02d616de4a77bc60b536485b..1c72248b08640e274dd43730b87f6a8ede270bc6 100644
--- a/third_party/WebKit/Source/core/html/HTMLCanvasElement.h
+++ b/third_party/WebKit/Source/core/html/HTMLCanvasElement.h
@@ -41,6 +41,7 @@
 #include "core/page/PageLifecycleObserver.h"
 #include "platform/geometry/FloatRect.h"
 #include "platform/geometry/IntSize.h"
+#include "platform/graphics/CanvasSurfaceLayerBridge.h"
 #include "platform/graphics/GraphicsTypes.h"
 #include "platform/graphics/GraphicsTypes3D.h"
 #include "platform/graphics/ImageBufferClient.h"
@@ -197,6 +198,10 @@ public:
     std::pair<Element*, String> getControlAndIdIfHitRegionExists(const LayoutPoint&);
     String getIdFromControl(const Element*);
 
+    // For OffscreenCanvas that controls this html canvas element
+    CanvasSurfaceLayerBridge* surfaceLayerBridge() const { return m_surfaceLayerBridge.get(); }
+    void createSurfaceLayerBridge();
+
 protected:
     void didMoveToNewDocument(Document& oldDocument) override;
 
@@ -246,6 +251,9 @@ private:
     OwnPtr<ImageBuffer> m_imageBuffer;
 
     mutable RefPtr<Image> m_copiedImage; // FIXME: This is temporary for platforms that have to copy the image buffer to render (and for CSSCanvasValue).
+
+    // Used for OffscreenCanvas that controls this HTML canvas element
+    OwnPtr<CanvasSurfaceLayerBridge> m_surfaceLayerBridge;
 };
 
 } // namespace blink