cc: Merge TileTaskRunner to TileTaskWorkerPool.

cc/raster/zero_copy_tile_task_worker_pool.cc

 // Copyright 2013 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/raster/zero_copy_tile_task_worker_pool.h"
 
 #include <stdint.h>
 
 #include <algorithm>
 
@@ skipping 71 matching lines @@
     ResourceFormat preferred_tile_format)
     : task_runner_(task_runner),
       task_graph_runner_(task_graph_runner),
       namespace_token_(task_graph_runner->GetNamespaceToken()),
       resource_provider_(resource_provider),
       preferred_tile_format_(preferred_tile_format) {}
 
 ZeroCopyTileTaskWorkerPool::~ZeroCopyTileTaskWorkerPool() {
 }
 
-TileTaskRunner* ZeroCopyTileTaskWorkerPool::AsTileTaskRunner() {
-  return this;
-}
-
 void ZeroCopyTileTaskWorkerPool::Shutdown() {
   TRACE_EVENT0("cc", "ZeroCopyTileTaskWorkerPool::Shutdown");
 
   TaskGraph empty;
   task_graph_runner_->ScheduleTasks(namespace_token_, &empty);
   task_graph_runner_->WaitForTasksToFinishRunning(namespace_token_);
 }
 
 void ZeroCopyTileTaskWorkerPool::ScheduleTasks(TaskGraph* graph) {
   TRACE_EVENT0("cc", "ZeroCopyTileTaskWorkerPool::ScheduleTasks");
@@ skipping 46 matching lines @@
   return base::WrapUnique<RasterBuffer>(
       new RasterBufferImpl(resource_provider_, resource));
 }
 
 void ZeroCopyTileTaskWorkerPool::ReleaseBufferForRaster(
     std::unique_ptr<RasterBuffer> buffer) {
   // Nothing to do here. RasterBufferImpl destructor cleans up after itself.
 }
 
 }  // namespace cc