cc: Speed up CleanUpImageDecodeTasks a bit.

cc/test/fake_tile_manager.cc

 // 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.
 
 #include "cc/test/fake_tile_manager.h"
 
 #include <deque>
 
 #include "cc/resources/raster_worker_pool.h"
 
@@ skipping 56 matching lines @@
   GetTilesWithAssignedBins(&all_tiles);
   AssignGpuMemoryToTiles(&all_tiles, &tiles_for_raster);
 }
 
 bool FakeTileManager::HasBeenAssignedMemory(Tile* tile) {
   return std::find(tiles_for_raster.begin(),
                    tiles_for_raster.end(),
                    tile) != tiles_for_raster.end();
 }
 
+void FakeTileManager::CheckForCompletedTasks() {
+  RasterWorkerPoolForTesting()->CheckForCompletedTasks();
+}
+
 }  // namespace cc