mash: Move more shelf files to ash/common/shelf.

ash/shelf/shelf_layout_manager_observer.h

-// 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.
-
-#ifndef ASH_SHELF_SHELF_LAYOUT_MANAGER_OBSERVER_H_
-#define ASH_SHELF_SHELF_LAYOUT_MANAGER_OBSERVER_H_
-
-#include "ash/ash_export.h"
-#include "ash/common/shelf/shelf_types.h"
-#include "ash/common/wm/background_animator.h"
-
-namespace aura {
-class Window;
-}
-
-namespace ash {
-
-class ASH_EXPORT ShelfLayoutManagerObserver {
- public:
-  virtual ~ShelfLayoutManagerObserver() {}
-
-  // Called when the target ShelfLayoutManager will be deleted.
-  virtual void WillDeleteShelfLayoutManager() {}
-
-  // Called when the visibility change is scheduled.
-  virtual void WillChangeVisibilityState(ShelfVisibilityState new_state) {}
-
-  // Called when the auto hide state is changed.
-  virtual void OnAutoHideStateChanged(ShelfAutoHideState new_state) {}
-
-  // Called when shelf background animation is started.
-  virtual void OnBackgroundUpdated(ShelfBackgroundType background_type,
-                                   BackgroundAnimatorChangeType change_type) {}
-};
-
-}  // namespace ash
-
-#endif  // ASH_SHELF_SHELF_LAYOUT_MANAGER_OBSERVER_H_