Moves ShellObserver to ash/common

ash/system/chromeos/session/logout_confirmation_controller.h

 // Copyright 2014 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_CHROMEOS_SESSION_LOGOUT_CONFIRMATION_CONTROLLER_H_
 #define ASH_SYSTEM_CHROMEOS_SESSION_LOGOUT_CONFIRMATION_CONTROLLER_H_
 
 #include <memory>
 
 #include "ash/ash_export.h"
-#include "ash/shell_observer.h"
+#include "ash/common/shell_observer.h"
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 
 namespace base {
 class TickClock;
 }
 
 namespace ash {
@@ skipping 39 matching lines @@
   base::TimeTicks logout_time_;
   LogoutConfirmationDialog* dialog_;  // Owned by the Views hierarchy.
   base::Timer logout_timer_;
 
   DISALLOW_COPY_AND_ASSIGN(LogoutConfirmationController);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_CHROMEOS_SESSION_LOGOUT_CONFIRMATION_CONTROLLER_H_