Moves ShellObserver to ash/common

ash/wm/lock_state_controller.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_WM_LOCK_STATE_CONTROLLER_H_
 #define ASH_WM_LOCK_STATE_CONTROLLER_H_
 
 #include <memory>
 
 #include "ash/ash_export.h"
-#include "ash/shell_observer.h"
+#include "ash/common/shell_observer.h"
 #include "ash/wm/lock_state_observer.h"
 #include "ash/wm/session_state_animator.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "base/time/time.h"
 #include "base/timer/elapsed_timer.h"
 #include "base/timer/timer.h"
 #include "ui/aura/window_tree_host_observer.h"
 
@@ skipping 318 matching lines @@
   base::Closure lock_screen_displayed_callback_;
 
   base::WeakPtrFactory<LockStateController> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(LockStateController);
 };
 
 }  // namespace ash
 
 #endif  // ASH_WM_LOCK_STATE_CONTROLLER_H_