Reland of 'Move content/browser/power_save_blocker to //device/power_save_blocker'

content/browser/loader/power_save_block_resource_throttle.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_LOADER_POWER_SAVE_BLOCK_RESOURCE_THROTTLE_H_
 #define CONTENT_BROWSER_LOADER_POWER_SAVE_BLOCK_RESOURCE_THROTTLE_H_
 
 #include <memory>
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/timer/timer.h"
 #include "content/public/browser/resource_throttle.h"
 
+namespace device {
+class PowerSaveBlocker;
+}  // namespace device
+
 namespace content {
 
-class PowerSaveBlocker;
-
 // This ResourceThrottle blocks power save until large upload request finishes.
 class PowerSaveBlockResourceThrottle : public ResourceThrottle {
  public:
   explicit PowerSaveBlockResourceThrottle(const std::string& host);
   ~PowerSaveBlockResourceThrottle() override;
 
   // ResourceThrottle overrides:
   void WillStartRequest(bool* defer) override;
   void WillProcessResponse(bool* defer) override;
   const char* GetNameForLogging() const override;
 
  private:
   void ActivatePowerSaveBlocker();
 
   const std::string host_;
   base::OneShotTimer timer_;
-  std::unique_ptr<PowerSaveBlocker> power_save_blocker_;
+  std::unique_ptr<device::PowerSaveBlocker> power_save_blocker_;
 
   DISALLOW_COPY_AND_ASSIGN(PowerSaveBlockResourceThrottle);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_LOADER_POWER_SAVE_BLOCK_RESOURCE_THROTTLE_H_