chromeos: Move files in //ash/common to //ash

ash/common/system/chromeos/network/network_observer.h

-// Copyright (c) 2012 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_NETWORK_NETWORK_OBSERVER_H_
-#define ASH_COMMON_SYSTEM_CHROMEOS_NETWORK_NETWORK_OBSERVER_H_
-
-namespace ash {
-
-class NetworkObserver {
- public:
-  virtual ~NetworkObserver() {}
-
-  // Called to request toggling Wi-Fi enable/disable, e.g. from an accelerator.
-  // NOTE: Toggling is asynchronous and subsequent calls to query the current
-  // state may return the old value.
-  virtual void RequestToggleWifi() = 0;
-};
-
-}  // namespace ash
-
-#endif  // ASH_COMMON_SYSTEM_CHROMEOS_NETWORK_NETWORK_OBSERVER_H_