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

base/power_monitor/power_monitor_ios.mm

-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// 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.
 
-#include "base/system_monitor/system_monitor.h"
+#include "base/power_monitor/power_monitor.h"
 
 #import <UIKit/UIKit.h>
 
 namespace base {
 
-void SystemMonitor::PlatformInit() {
+void PowerMonitor::PlatformInit() {
   NSNotificationCenter* nc = [NSNotificationCenter defaultCenter];
   id foreground =
       [nc addObserverForName:UIApplicationWillEnterForegroundNotification
                       object:nil
                        queue:nil
                   usingBlock:^(NSNotification* notification) {
-                      ProcessPowerMessage(RESUME_EVENT);
+                      ProcessPowerEvent(RESUME_EVENT);
                   }];
   id background =
       [nc addObserverForName:UIApplicationDidEnterBackgroundNotification
                       object:nil
                        queue:nil
                   usingBlock:^(NSNotification* notification) {
-                      ProcessPowerMessage(SUSPEND_EVENT);
+                      ProcessPowerEvent(SUSPEND_EVENT);
                   }];
   notification_observers_.push_back(foreground);
   notification_observers_.push_back(background);
 }
 
-void SystemMonitor::PlatformDestroy() {
+void PowerMonitor::PlatformDestroy() {
   NSNotificationCenter* nc = [NSNotificationCenter defaultCenter];
   for (std::vector<id>::iterator it = notification_observers_.begin();
        it != notification_observers_.end(); ++it) {
     [nc removeObserver:*it];
   }
   notification_observers_.clear();
 }
 
 }  // namespace base