Shuffles and renames ash/common/wm classes

ash/common/wm/wm_root_window_controller_observer.h

-// Copyright 2016 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_WM_WM_ROOT_WINDOW_CONTROLLER_OBSERVER_H_
-#define ASH_COMMON_WM_WM_ROOT_WINDOW_CONTROLLER_OBSERVER_H_
-
-#include "ash/ash_export.h"
-
-namespace ash {
-namespace wm {
-
-class WmWindow;
-
-class ASH_EXPORT WmRootWindowControllerObserver {
- public:
-  virtual void OnWorkAreaChanged() {}
-  virtual void OnFullscreenStateChanged(bool is_fullscreen) {}
-  virtual void OnShelfAlignmentChanged() {}
-
- protected:
-  virtual ~WmRootWindowControllerObserver() {}
-};
-
-}  // namespace wm
-}  // namespace ash
-
-#endif  // ASH_COMMON_WM_WM_ROOT_WINDOW_CONTROLLER_OBSERVER_H_