Revert the merge. Mac build is mysteriously broken.

third_party/WebKit/WebCore/rendering/RenderLayerBacking.h

 /*
  * 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 19 matching lines @@
 
 #include "FloatPoint.h"
 #include "FloatPoint3D.h"
 #include "GraphicsLayer.h"
 #include "GraphicsLayerClient.h"
 #include "RenderLayer.h"
 #include "TransformationMatrix.h"
 
 namespace WebCore {
 
-class KeyframeList;
 class RenderLayerCompositor;
 
 // RenderLayerBacking controls the compositing behavior for a single RenderLayer.
 // It holds the various GraphicsLayers, and makes decisions about intra-layer rendering
 // optimizations.
 // 
 // There is one RenderLayerBacking for each RenderLayer that is composited.
 
 class RenderLayerBacking : public GraphicsLayerClient {
 public:
@@ skipping 59 matching lines @@
     virtual void notifyAnimationStarted(const GraphicsLayer*, double startTime);
 
     virtual void paintContents(const GraphicsLayer*, GraphicsContext&, GraphicsLayerPaintingPhase, const IntRect& clip);
 
     virtual IntRect contentsBox(const GraphicsLayer*);
     
 private:
     void createGraphicsLayer();
     void destroyGraphicsLayer();
 
-    RenderBoxModelObject* renderer() const { return m_owningLayer->renderer(); }
+    RenderBox* renderer() const { return m_owningLayer->renderer(); }
     RenderLayerCompositor* compositor() const { return m_owningLayer->compositor(); }
 
     bool updateClippingLayers(bool needsAncestorClip, bool needsDescendantClip);
     bool updateContentsLayer(bool needsContentsLayer);
 
     IntSize contentOffsetInCompostingLayer();
     // Result is transform origin in pixels.
     FloatPoint computeTransformOrigin(const IntRect& borderBox) const;
 
     void updateLayerOpacity();
@@ skipping 33 matching lines @@
     bool m_simpleCompositingLayerStatusDirty : 1; // set if the test for simple layers needs to be redone
 
     bool m_compositingContentOffsetDirty: 1;
 };
 
 } // namespace WebCore
 
 #endif // USE(ACCELERATED_COMPOSITING)
 
 #endif // RenderLayerBacking_h