cc: Avoid expensive RenderingStats collection.

cc/tile_manager.h

 // Copyright 2012 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_TILE_MANAGER_H_
 #define CC_TILE_MANAGER_H_
 
 #include <list>
 #include <queue>
 #include <vector>
@@ skipping 75 matching lines @@
 };
 
 // This class manages tiles, deciding which should get rasterized and which
 // should no longer have any memory assigned to them. Tile objects are "owned"
 // by layers; they automatically register with the manager when they are
 // created, and unregister from the manager when they are deleted.
 class CC_EXPORT TileManager {
  public:
   TileManager(TileManagerClient* client,
               ResourceProvider *resource_provider,
-              size_t num_raster_threads);
+              size_t num_raster_threads,
+              bool record_rendering_stats);
   virtual ~TileManager();
 
   const GlobalStateThatImpactsTilePriority& GlobalState() const {
       return global_state_;
   }
   void SetGlobalState(const GlobalStateThatImpactsTilePriority& state);
 
   void ManageTiles();
   void CheckForCompletedTileUploads();
 
@@ skipping 55 matching lines @@
   TileList tiles_with_image_decoding_tasks_;
 
   typedef base::hash_map<uint32_t, skia::LazyPixelRef*> PixelRefMap;
   PixelRefMap pending_decode_tasks_;
 
   typedef std::queue<scoped_refptr<Tile> > TileQueue;
   TileQueue tiles_with_pending_set_pixels_;
   size_t bytes_pending_set_pixels_;
   bool ever_exceeded_memory_budget_;
 
+  bool record_rendering_stats_;
   RenderingStats rendering_stats_;
 
   int raster_state_count_[NUM_STATES][NUM_TREES][NUM_BINS];
 
   DISALLOW_COPY_AND_ASSIGN(TileManager);
 };
 
 }  // namespace cc
 
 #endif  // CC_TILE_MANAGER_H_