Moves ShellObserver to ash/common

ash/root_window_controller.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_ROOT_WINDOW_CONTROLLER_H_
 #define ASH_ROOT_WINDOW_CONTROLLER_H_
 
 #include <map>
 #include <memory>
 
 #include "ash/ash_export.h"
 #include "ash/common/shelf/shelf_types.h"
-#include "ash/shell_observer.h"
+#include "ash/common/shell_observer.h"
 #include "ash/system/user/login_status.h"
 #include "base/macros.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_tree_host.h"
 #include "ui/base/ui_base_types.h"
 
 class SkBitmap;
 
 namespace aura {
 class EventFilter;
@@ skipping 310 matching lines @@
 
 // On classic ash, returns the RootWindowController for the given |root_window|.
 // On mus ash, returns the RootWindowController for the primary display.
 // See RootWindowController class comment above.
 ASH_EXPORT RootWindowController* GetRootWindowController(
     const aura::Window* root_window);
 
 }  // namespace ash
 
 #endif  // ASH_ROOT_WINDOW_CONTROLLER_H_