Revert of Pass SequencedTaskRunner to PowerSaveBlocker for ui/file operations

content/browser/power_save_blocker_factory.cc

-// Copyright 2016 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 "content/public/browser/power_save_blocker_factory.h"
-
-#include "base/threading/sequenced_worker_pool.h"
-#include "content/public/browser/browser_thread.h"
-
-namespace content {
-
-std::unique_ptr<PowerSaveBlocker> CreatePowerSaveBlocker(
-    PowerSaveBlocker::PowerSaveBlockerType type,
-    PowerSaveBlocker::Reason reason,
-    const std::string& description) {
-  base::SequencedWorkerPool::SequenceToken token =
-      base::SequencedWorkerPool::GetSequenceToken();
-  return PowerSaveBlocker::CreateWithTaskRunners(
-      type, reason, description,
-      BrowserThread::GetMessageLoopProxyForThread(BrowserThread::UI),
-      BrowserThread::GetBlockingPool()->GetSequencedTaskRunner(token));
-}
-
-}  // namespace content