Revert of Pass SequencedTaskRunner to PowerSaveBlocker for ui/file operations

content/browser/power_save_blocker_impl.h

 // Copyright (c) 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.
 
 #ifndef CONTENT_BROWSER_POWER_SAVE_BLOCKER_IMPL_H_
 #define CONTENT_BROWSER_POWER_SAVE_BLOCKER_IMPL_H_
 
 #include <string>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "build/build_config.h"
 #include "content/public/browser/power_save_blocker.h"
 
 namespace content {
 
 class WebContents;
 
 class PowerSaveBlockerImpl : public PowerSaveBlocker {
  public:
-  PowerSaveBlockerImpl(
-      PowerSaveBlockerType type,
-      Reason reason,
-      const std::string& description,
-      scoped_refptr<base::SequencedTaskRunner> ui_task_runner,
-      scoped_refptr<base::SequencedTaskRunner> blocking_task_runner);
+  PowerSaveBlockerImpl(PowerSaveBlockerType type,
+                       Reason reason,
+                       const std::string& description);
   ~PowerSaveBlockerImpl() override;
 
 #if defined(OS_ANDROID)
   // In Android platform, the kPowerSaveBlockPreventDisplaySleep type of
   // PowerSaveBlocker should associated with a WebContents, so the blocker
   // could be removed by platform if the WebContents is hidden.
   void InitDisplaySleepBlocker(WebContents* web_contents);
 #endif
 
  private:
@@ skipping 11 matching lines @@
   // };
   scoped_refptr<Delegate> delegate_;
 
 #if defined(USE_X11)
   // Since display sleep prevention also implies system suspend prevention, for
   // the Linux FreeDesktop API case, there needs to be a second delegate to
   // block system suspend when screen saver / display sleep is blocked.
   scoped_refptr<Delegate> freedesktop_suspend_delegate_;
 #endif
 
-  scoped_refptr<base::SequencedTaskRunner> ui_task_runner_;
-  scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_;
-
   DISALLOW_COPY_AND_ASSIGN(PowerSaveBlockerImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_POWER_SAVE_BLOCKER_IMPL_H_