Added a vector to TileManager to explicitly track live or allocated tiles.

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 167 matching lines @@
 
   TileManagerClient* client_;
   scoped_ptr<ResourcePool> resource_pool_;
   scoped_ptr<RasterWorkerPool> raster_worker_pool_;
   bool manage_tiles_pending_;
   int manage_tiles_call_count_;
 
   GlobalStateThatImpactsTilePriority global_state_;
 
   typedef std::vector<Tile*> TileVector;
-  TileVector tiles_;
+  TileVector all_tiles_;
+  TileVector live_or_allocated_tiles_;
   TileVector tiles_that_need_to_be_rasterized_;
 
   typedef std::list<Tile*> TileList;
   // Tiles with image decoding tasks. These tiles need to be rasterized
   // when all the image decoding tasks finish.
   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_;
   MemoryHistory::Entry memory_stats_from_last_assign_;
 
   bool record_rendering_stats_;
   RenderingStats rendering_stats_;
 
   bool use_cheapness_estimator_;
   int raster_state_count_[NUM_STATES][NUM_TREES][NUM_BINS];
 
   DISALLOW_COPY_AND_ASSIGN(TileManager);
 };
 
 }  // namespace cc
 
 #endif  // CC_TILE_MANAGER_H_