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->isRenderIFrame() || renderer->isFrame()) && toHTMLFrameOwnerElement(renderer->node())->contentFrame() && toHTMLFrameOwnerElement(renderer->node())->contentFrame()->platformLayer()) {

[eseidel, 2013/12/11 18:50:01]

Don't we have a frame base class for these both?  Maybe you just want to just
grab the node and see if the node is a  frameOwnerElement directly?

[kenrb, 2013/12/11 22:44:56]

The base class (RenderFrameBase) was removed a few months ago because it turned
out to have only code that wasn't relevant to Blink. But I've implemented your
suggestion.

+        m_graphicsLayer->setContentsToPlatformLayer(toHTMLFrameOwnerElement(renderer->node())->contentFrame()->platformLayer());

[eseidel, 2013/12/11 18:50:01]

You just if-checked this long lookup, maybe you wanted to save it in a local?

[kenrb, 2013/12/11 22:44:56]

Done.

     } 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