| // 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. | 
 |  | 
 | #ifndef BASE_POWER_MONITOR_POWER_OBSERVER_H_ | 
 | #define BASE_POWER_MONITOR_POWER_OBSERVER_H_ | 
 |  | 
 | #include "base/base_export.h" | 
 | #include "base/compiler_specific.h" | 
 |  | 
 | namespace base { | 
 |  | 
 | class BASE_EXPORT PowerObserver { | 
 |  public: | 
 |   // Notification of a change in power status of the computer, such | 
 |   // as from switching between battery and A/C power. | 
 |   virtual void OnPowerStateChange(bool on_battery_power) {}; | 
 |  | 
 |   // Notification that the system is suspending. | 
 |   virtual void OnSuspend() {} | 
 |  | 
 |   // Notification that the system is resuming. | 
 |   virtual void OnResume() {} | 
 |  | 
 |  protected: | 
 |   virtual ~PowerObserver() = default; | 
 | }; | 
 |  | 
 | }  // namespace base | 
 |  | 
 | #endif  // BASE_POWER_MONITOR_POWER_OBSERVER_H_ |