cc: Avoid expensive RenderingStats collection.

cc/layer_updater.h

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_LAYER_UPDATER_H_
 #define CC_LAYER_UPDATER_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "cc/cc_export.h"
@@ skipping 16 matching lines @@
 public:
     // Allows updaters to store per-resource update properties.
     class CC_EXPORT Resource {
     public:
         virtual ~Resource();
 
         PrioritizedResource* texture() { return m_texture.get(); }
         void swapTextureWith(scoped_ptr<PrioritizedResource>& texture);
         // TODO(reveman): partialUpdate should be a property of this class
         // instead of an argument passed to update().
-        virtual void update(ResourceUpdateQueue&, const gfx::Rect& sourceRect, const gfx::Vector2d& destOffset, bool partialUpdate, RenderingStats&) = 0;
+        virtual void update(ResourceUpdateQueue&, const gfx::Rect& sourceRect, const gfx::Vector2d& destOffset, bool partialUpdate, RenderingStats*) = 0;
     protected:
         explicit Resource(scoped_ptr<PrioritizedResource> texture);
 
     private:
         scoped_ptr<PrioritizedResource> m_texture;
 
         DISALLOW_COPY_AND_ASSIGN(Resource);
     };
 
     LayerUpdater() { }
 
     virtual scoped_ptr<Resource> createResource(PrioritizedResourceManager*) = 0;
     // The |resultingOpaqueRect| gives back a region of the layer that was painted opaque. If the layer is marked opaque in the updater,
     // then this region should be ignored in preference for the entire layer's area.
-    virtual void prepareToUpdate(const gfx::Rect& contentRect, const gfx::Size& tileSize, float contentsWidthScale, float contentsHeightScale, gfx::Rect& resultingOpaqueRect, RenderingStats&) { }
+    virtual void prepareToUpdate(const gfx::Rect& contentRect, const gfx::Size& tileSize, float contentsWidthScale, float contentsHeightScale, gfx::Rect& resultingOpaqueRect, RenderingStats*) { }
 
     // Set true by the layer when it is known that the entire output is going to be opaque.
     virtual void setOpaque(bool) { }
 
 protected:
     virtual ~LayerUpdater() { }
 
 private:
     friend class base::RefCounted<LayerUpdater>;
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYER_UPDATER_H_