mash: Migrate tray IME view to wm common types, move to //ash/common

ash/system/ime/ime_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_SYSTEM_IME_IME_OBSERVER_H_
-#define ASH_SYSTEM_IME_IME_OBSERVER_H_
-
-namespace ash {
-
-class IMEObserver {
- public:
-  virtual ~IMEObserver() {}
-
-  // Notify the observer that the IME state has changed, and should be
-  // refreshed.
-  virtual void OnIMERefresh() = 0;
-
-  // Notify the observer that the IME menu activation state has changed, and
-  // should be refreshed. |is_active| represents whether the new IME menu is
-  // active, and IME related items in system tray should be removed if
-  // |is_active| is true.
-  virtual void OnIMEMenuActivationChanged(bool is_active) = 0;
-};
-
-}  // namespace ash
-
-#endif  // ASH_SYSTEM_IME_IME_OBSERVER_H_