Insert pinch zoom virtual viewport layers to graphics layer tree.

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 1427 matching lines @@
     return m_renderView->layer();
 }
 
 GraphicsLayer* RenderLayerCompositor::rootGraphicsLayer() const
 {
     if (m_overflowControlsHostLayer)
         return m_overflowControlsHostLayer.get();
     return m_rootContentLayer.get();
 }
 
+GraphicsLayer* RenderLayerCompositor::clipLayer() const
+{
+    return m_clipLayer.get();
+}
+
 GraphicsLayer* RenderLayerCompositor::scrollLayer() const
 {
     return m_scrollLayer.get();
 }
 
 void RenderLayerCompositor::setIsInWindow(bool isInWindow)
 {
     if (!inCompositingMode())
         return;
 
@@ skipping 1303 matching lines @@
     info.addMember(m_layerForScrollCorner, "layerForScrollCorner");
 #if ENABLE(RUBBER_BANDING)
     info.addMember(m_layerForOverhangAreas, "layerForOverhangAreas");
     info.addMember(m_contentShadowLayer, "contentShadowLayer");
     info.addMember(m_layerForTopOverhangArea, "layerForTopOverhangArea");
     info.addMember(m_layerForBottomOverhangArea, "layerForBottomOverhangArea");
 #endif
 }
 
 } // namespace WebCore