Add Frame::isMainFrame and deploy it

Source/core/rendering/RenderLayerCompositor.cpp

 /*
  * Copyright (C) 2009, 2010 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 2243 matching lines @@
     m_rootLayerAttachment = RootLayerUnattached;
 }
 
 void RenderLayerCompositor::updateRootLayerAttachment()
 {
     ensureRootLayer();
 }
 
 bool RenderLayerCompositor::isMainFrame() const
 {
+    // FIXME: Frame::isMainFrame() is probably better.
     return !m_renderView->document().ownerElement();
 }
 
 // IFrames are special, because we hook compositing layers together across iframe boundaries
 // when both parent and iframe content are composited. So when this frame becomes composited, we have
 // to use a synthetic style change to get the iframes into RenderLayers in order to allow them to composite.
 void RenderLayerCompositor::notifyIFramesOfCompositingChange()
 {
     if (!m_renderView->frameView())
         return;
@@ skipping 174 matching lines @@
     } else if (graphicsLayer == m_scrollLayer.get()) {
         name = "Frame Scrolling Layer";
     } else {
         ASSERT_NOT_REACHED();
     }
 
     return name;
 }
 
 } // namespace WebCore