|  | // Copyright (c) 2011 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_TIMER_HI_RES_TIMER_MANAGER_H_ | 
|  | #define BASE_TIMER_HI_RES_TIMER_MANAGER_H_ | 
|  |  | 
|  | #include "base/base_export.h" | 
|  | #include "base/macros.h" | 
|  | #include "base/memory/ref_counted.h" | 
|  | #include "base/timer/timer.h" | 
|  | #include "build_config.h" | 
|  |  | 
|  | namespace base { | 
|  |  | 
|  | // Ensures that the Windows high resolution timer is only used | 
|  | // when not running on battery power. | 
|  | class BASE_EXPORT HighResolutionTimerManager { | 
|  | public: | 
|  | HighResolutionTimerManager(); | 
|  | ~HighResolutionTimerManager(); | 
|  |  | 
|  | // Returns true if the hi resolution clock could be used right now. | 
|  | bool hi_res_clock_available() const { return hi_res_clock_available_; } | 
|  |  | 
|  | private: | 
|  | // Enable or disable the faster multimedia timer. | 
|  | void UseHiResClock(bool use); | 
|  |  | 
|  | bool hi_res_clock_available_; | 
|  |  | 
|  | #if defined(OS_WIN) | 
|  | // Timer for polling the high resolution timer usage. | 
|  | base::RepeatingTimer timer_; | 
|  | #endif | 
|  |  | 
|  | DISALLOW_COPY_AND_ASSIGN(HighResolutionTimerManager); | 
|  | }; | 
|  |  | 
|  | }  // namespace base | 
|  |  | 
|  | #endif  // BASE_TIMER_HI_RES_TIMER_MANAGER_H_ |