chromeos: Move files in //ash/common to //ash, part 1

ash/common/system/chromeos/power/battery_notification.h

-// Copyright 2015 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 ASH_COMMON_SYSTEM_CHROMEOS_POWER_BATTERY_NOTIFICATION_H_
-#define ASH_COMMON_SYSTEM_CHROMEOS_POWER_BATTERY_NOTIFICATION_H_
-
-#include "ash/ash_export.h"
-#include "ash/common/system/chromeos/power/tray_power.h"
-#include "base/macros.h"
-
-namespace message_center {
-class MessageCenter;
-}
-
-namespace ash {
-
-// Class for showing and hiding a MessageCenter low battery notification.
-class ASH_EXPORT BatteryNotification {
- public:
-  BatteryNotification(message_center::MessageCenter* message_center,
-                      TrayPower::NotificationState notification_state);
-  ~BatteryNotification();
-
-  // Updates the notification if it still exists.
-  void Update(TrayPower::NotificationState notification_state);
-
- private:
-  message_center::MessageCenter* message_center_;
-
-  DISALLOW_COPY_AND_ASSIGN(BatteryNotification);
-};
-
-}  // namespace ash
-
-#endif  // ASH_COMMON_SYSTEM_CHROMEOS_POWER_BATTERY_NOTIFICATION_H_