Add an alternate paintContents method to WebContentLayerClient.

Source/platform/graphics/GraphicsLayer.cpp

 /*
  * Copyright (C) 2009 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 94 matching lines @@
     , m_contentsLayer(0)
     , m_contentsLayerId(0)
     , m_scrollableArea(0)
     , m_3dRenderingContext(0)
 {
 #if ENABLE(ASSERT)
     if (m_client)
         m_client->verifyNotPainting();
 #endif
 
-    m_opaqueRectTrackingContentLayerDelegate = adoptPtr(new OpaqueRectTrackingContentLayerDelegate(this));
-    m_layer = adoptPtr(Platform::current()->compositorSupport()->createContentLayer(m_opaqueRectTrackingContentLayerDelegate.get()));
+    m_contentLayerDelegate = adoptPtr(new ContentLayerDelegate(this));
+    m_layer = adoptPtr(Platform::current()->compositorSupport()->createContentLayer(m_contentLayerDelegate.get()));
     m_layer->layer()->setDrawsContent(m_drawsContent && m_contentsVisible);
     m_layer->layer()->setWebLayerClient(this);
     m_layer->setAutomaticallyComputeRasterScale(true);
 }
 
 GraphicsLayer::~GraphicsLayer()
 {
     for (size_t i = 0; i < m_linkHighlights.size(); ++i)
         m_linkHighlights[i]->clearCurrentGraphicsLayer();
     m_linkHighlights.clear();
@@ skipping 690 matching lines @@
         return;
 
     m_backgroundColor = color;
     m_layer->layer()->setBackgroundColor(m_backgroundColor.rgb());
 }
 
 void GraphicsLayer::setContentsOpaque(bool opaque)
 {
     m_contentsOpaque = opaque;
     m_layer->layer()->setOpaque(m_contentsOpaque);
-    m_opaqueRectTrackingContentLayerDelegate->setOpaque(m_contentsOpaque);
+    m_contentLayerDelegate->setOpaque(m_contentsOpaque);
     clearContentsLayerIfUnregistered();
     if (m_contentsLayer)
         m_contentsLayer->setOpaque(opaque);
 }
 
 void GraphicsLayer::setMaskLayer(GraphicsLayer* maskLayer)
 {
     if (maskLayer == m_maskLayer)
         return;
 
@@ skipping 224 matching lines @@
 #ifndef NDEBUG
 void showGraphicsLayerTree(const blink::GraphicsLayer* layer)
 {
     if (!layer)
         return;
 
     String output = layer->layerTreeAsText(blink::LayerTreeIncludesDebugInfo);
     fprintf(stderr, "%s\n", output.utf8().data());
 }
 #endif