Add CanvasSurfaceLayerBridge

third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp

Index: third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp
diff --git a/third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp b/third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp
index 57eeda916ab7246c8b4a67294ae3ca4249041205..eefb88370c1e808f4b07c4a53b20fb7db212ac42 100644
--- a/third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp
+++ b/third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp
@@ -123,6 +123,16 @@ static inline bool isAcceleratedCanvas(const LayoutObject* layoutObject)
     return false;
 }
 
+static inline bool isCanvasTransferedFromOffscreen(const LayoutObject* layoutObject)

[Justin Novosad, 2016/05/20 19:58:26]

isCanvasControlledByOffscreen

+{
+    if (layoutObject->isCanvas()) {
+        HTMLCanvasElement* canvas = toHTMLCanvasElement(layoutObject->node());
+        if (!!canvas->surfaceLayerBridge())

[Justin Novosad, 2016/05/20 19:58:26]

"!!" is not necessary

+            return true;
+    }
+    return false;
+}
+
 static bool hasBoxDecorationsOrBackgroundImage(const ComputedStyle& style)
 {
     return style.hasBoxDecorations() || style.hasBackgroundImage();
@@ -538,6 +548,10 @@ bool CompositedLayerMapping::updateGraphicsLayerConfiguration()
     } else if (layoutObject->isVideo()) {
         HTMLMediaElement* mediaElement = toHTMLMediaElement(layoutObject->node());
         m_graphicsLayer->setContentsToPlatformLayer(mediaElement->platformLayer());
+    } else if (isCanvasTransferedFromOffscreen(layoutObject)) {
+        HTMLCanvasElement* canvas = toHTMLCanvasElement(layoutObject->node());
+        m_graphicsLayer->setContentsToPlatformLayer(canvas->surfaceLayerBridge()->getWebLayer());
+        layerConfigChanged = true;
     } else if (isAcceleratedCanvas(layoutObject)) {
         HTMLCanvasElement* canvas = toHTMLCanvasElement(layoutObject->node());
         if (CanvasRenderingContext* context = canvas->renderingContext())