Attach a WebLayer to a frame element for out-of-process iframes.

Source/core/rendering/CompositedLayerMapping.cpp

 /*
  * Copyright (C) 2009, 2010, 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 486 matching lines @@
     }
 
     updateBackgroundColor(isSimpleContainerCompositingLayer());
 
     if (isDirectlyCompositedImage())
         updateImageContents();
 
     if (renderer->isEmbeddedObject() && toRenderEmbeddedObject(renderer)->allowsAcceleratedCompositing()) {
         PluginView* pluginView = toPluginView(toRenderWidget(renderer)->widget());
         m_graphicsLayer->setContentsToPlatformLayer(pluginView->platformLayer());
+    } else if (renderer->node() && renderer->node()->isFrameOwnerElement() && toHTMLFrameOwnerElement(renderer->node())->contentFrame()) {
+        blink::WebLayer* layer = toHTMLFrameOwnerElement(renderer->node())->contentFrame()->remotePlatformLayer();
+        if (layer)
+            m_graphicsLayer->setContentsToPlatformLayer(layer);
     } else if (renderer->isVideo()) {
         HTMLMediaElement* mediaElement = toHTMLMediaElement(renderer->node());
         m_graphicsLayer->setContentsToPlatformLayer(mediaElement->platformLayer());
     } else if (isAcceleratedCanvas(renderer)) {
         HTMLCanvasElement* canvas = toHTMLCanvasElement(renderer->node());
         if (CanvasRenderingContext* context = canvas->renderingContext())
             m_graphicsLayer->setContentsToPlatformLayer(context->platformLayer());
         layerConfigChanged = true;
     }
     if (renderer->isRenderPart())
@@ skipping 1531 matching lines @@
     } else if (graphicsLayer == m_scrollingContentsLayer.get()) {
         name = "Scrolling Contents Layer";
     } else {
         ASSERT_NOT_REACHED();
     }
 
     return name;
 }
 
 } // namespace WebCore