cc: Speed up CleanUpImageDecodeTasks a bit.

cc/test/fake_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_TEST_FAKE_TILE_MANAGER_H_
 #define  CC_TEST_FAKE_TILE_MANAGER_H_
 
 #include <set>
 #include <vector>
 
 #include "cc/resources/tile_manager.h"
 
 namespace cc {
 
 class FakeTileManager : public TileManager {
  public:
   explicit FakeTileManager(TileManagerClient* client);
   FakeTileManager(TileManagerClient* client,
                   ResourceProvider* resource_provider);
 
   bool HasBeenAssignedMemory(Tile* tile);
   void AssignMemoryToTiles();
 
+  void CheckForCompletedTasks();
+
   virtual ~FakeTileManager();
 
   std::vector<Tile*> tiles_for_raster;
   PrioritizedTileSet all_tiles;
 };
 
 }  // namespace cc
 
 #endif  // CC_TEST_FAKE_TILE_MANAGER_H_