SystemMonitor refactoring: move power state monitor into a separate class called PowerMonitor

base/power_monitor/power_monitor_win.cc

 // 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.
 
-#include "base/system_monitor/system_monitor.h"
+#include "base/power_monitor/power_monitor.h"
 
 namespace base {
 
-void SystemMonitor::ProcessWmPowerBroadcastMessage(int event_id) {
+void PowerMonitor::ProcessWmPowerBroadcastMessage(int event_id) {
   PowerEvent power_event;
   switch (event_id) {
     case PBT_APMPOWERSTATUSCHANGE:  // The power status changed.
       power_event = POWER_STATE_EVENT;
       break;
     case PBT_APMRESUMEAUTOMATIC:  // Resume from suspend.
     //case PBT_APMRESUMESUSPEND:  // User-initiated resume from suspend.
                                   // We don't notify for this latter event
                                   // because if it occurs it is always sent as a
                                   // second event after PBT_APMRESUMEAUTOMATIC.
       power_event = RESUME_EVENT;
       break;
     case PBT_APMSUSPEND:  // System has been suspended.
       power_event = SUSPEND_EVENT;
       break;
     default:
       return;
 
     // Other Power Events:
     // PBT_APMBATTERYLOW - removed in Vista.
     // PBT_APMOEMEVENT - removed in Vista.
     // PBT_APMQUERYSUSPEND - removed in Vista.
     // PBT_APMQUERYSUSPENDFAILED - removed in Vista.
     // PBT_APMRESUMECRITICAL - removed in Vista.
     // PBT_POWERSETTINGCHANGE - user changed the power settings.
   }
-  ProcessPowerMessage(power_event);
+  ProcessPowerEvent(power_event);
+}
+
+void PowerMonitor::PlatformInit() {
+}
+
+void PowerMonitor::PlatformDestroy() {
 }
 
 // Function to query the system to see if it is currently running on
 // battery power.  Returns true if running on battery.
-bool SystemMonitor::IsBatteryPower() {
+bool PowerMonitor::IsBatteryPower() {
   SYSTEM_POWER_STATUS status;
   if (!GetSystemPowerStatus(&status)) {
     DLOG(ERROR) << "GetSystemPowerStatus failed: " << GetLastError();
     return false;
   }
   return (status.ACLineStatus == 0);
 }
 
 }  // namespace base