base/hi_res_timer_manager_win.cc

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/hi_res_timer_manager.h"
   6
   7 #include "base/time.h"
   8
   9 HighResolutionTimerManager::HighResolutionTimerManager()
  10     : hi_res_clock_available_(false) {
  11   base::SystemMonitor* system_monitor = base::SystemMonitor::Get();
  12   system_monitor->AddPowerObserver(this);
  13   UseHiResClock(!system_monitor->BatteryPower());
  14 }
  15
  16 HighResolutionTimerManager::~HighResolutionTimerManager() {
  17   base::SystemMonitor::Get()->RemovePowerObserver(this);
  18   UseHiResClock(false);
  19 }
  20
  21 void HighResolutionTimerManager::OnPowerStateChange(bool on_battery_power) {
  22   UseHiResClock(!on_battery_power);
  23 }
  24
  25 void HighResolutionTimerManager::UseHiResClock(bool use) {
  26   if (use == hi_res_clock_available_)
  27     return;
  28   hi_res_clock_available_ = use;
  29   base::Time::EnableHighResolutionTimer(use);
  30 }