chromeos: Move files in //ash/common to //ash, part 1

ash/system/session/logout_confirmation_dialog.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_COMMON_SYSTEM_CHROMEOS_SESSION_LOGOUT_CONFIRMATION_DIALOG_H_
-#define ASH_COMMON_SYSTEM_CHROMEOS_SESSION_LOGOUT_CONFIRMATION_DIALOG_H_
+#ifndef ASH_SYSTEM_SESSION_LOGOUT_CONFIRMATION_DIALOG_H_
+#define ASH_SYSTEM_SESSION_LOGOUT_CONFIRMATION_DIALOG_H_
 
 #include "base/macros.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 #include "ui/views/window/dialog_delegate.h"
 
 namespace views {
 class Label;
 }
 
@@ skipping 30 matching lines @@
 
   views::Label* label_;
 
   base::RepeatingTimer update_timer_;
 
   DISALLOW_COPY_AND_ASSIGN(LogoutConfirmationDialog);
 };
 
 }  // namespace ash
 
-#endif  // ASH_COMMON_SYSTEM_CHROMEOS_SESSION_LOGOUT_CONFIRMATION_DIALOG_H_
+#endif  // ASH_SYSTEM_SESSION_LOGOUT_CONFIRMATION_DIALOG_H_