services/ui: Remove deprecated gpu code

services/ui/gles2/raster_thread_helper.cc

-// Copyright 2015 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 "services/ui/gles2/raster_thread_helper.h"
-
-#include "base/logging.h"
-#include "base/threading/simple_thread.h"
-#include "cc/raster/single_thread_task_graph_runner.h"
-
-namespace gles2 {
-
-RasterThreadHelper::RasterThreadHelper()
-    : task_graph_runner_(new cc::SingleThreadTaskGraphRunner) {
-  task_graph_runner_->Start("CompositorTileWorker1",
-                            base::SimpleThread::Options());
-}
-
-RasterThreadHelper::~RasterThreadHelper() {
-  task_graph_runner_->Shutdown();
-}
-
-cc::TaskGraphRunner* RasterThreadHelper::task_graph_runner() {
-  return task_graph_runner_.get();
-}
-
-}  // namespace gles2