Merge M54: "Implement base::PowerMonitor::IsOnBatteryPower() for OSX."

base/power_monitor/power_monitor_device_source_ios.mm

 // 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/power_monitor/power_monitor_device_source.h"
 
 #import <UIKit/UIKit.h>
 
 namespace base {
 
+bool PowerMonitorDeviceSource::IsOnBatteryPowerImpl() {
+  NOTIMPLEMENTED();
+  return false;
+}
+
 void PowerMonitorDeviceSource::PlatformInit() {
   NSNotificationCenter* nc = [NSNotificationCenter defaultCenter];
   id foreground =
       [nc addObserverForName:UIApplicationWillEnterForegroundNotification
                       object:nil
                        queue:nil
                   usingBlock:^(NSNotification* notification) {
                       ProcessPowerEvent(RESUME_EVENT);
                   }];
   id background =
@@ skipping 10 matching lines @@
 void PowerMonitorDeviceSource::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