Revert of cc: Remove WorkerPool class and instead use TaskGraphRunner directly.

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 <limits>
 
 #include "cc/resources/raster_worker_pool.h"
@@ skipping 55 matching lines @@
 
 FakeTileManager::FakeTileManager(TileManagerClient* client,
                                  ResourceProvider* resource_provider,
                                  size_t raster_task_limit_bytes)
     : TileManager(client,
                   resource_provider,
                   make_scoped_ptr<RasterWorkerPool>(new FakeRasterWorkerPool),
                   raster_task_limit_bytes,
                   NULL) {}
 
-FakeTileManager::~FakeTileManager() {
-  RasterWorkerPoolForTesting()->Shutdown();
-  RasterWorkerPoolForTesting()->CheckForCompletedTasks();
-}
+FakeTileManager::~FakeTileManager() {}
 
 void FakeTileManager::AssignMemoryToTiles(
     const GlobalStateThatImpactsTilePriority& state) {
   tiles_for_raster.clear();
   all_tiles.Clear();
 
   SetGlobalStateForTesting(state);
   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();
 }
 
 void FakeTileManager::Release(Tile* tile) {
   TileManager::Release(tile);
   CleanUpReleasedTiles();
 }
 
 }  // namespace cc