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

ash/system/screen_layout_observer.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_SYSTEM_CHROMEOS_SCREEN_LAYOUT_OBSERVER_H_
-#define ASH_SYSTEM_CHROMEOS_SCREEN_LAYOUT_OBSERVER_H_
+#ifndef ASH_SYSTEM_SCREEN_LAYOUT_OBSERVER_H_
+#define ASH_SYSTEM_SCREEN_LAYOUT_OBSERVER_H_
 
 #include <stdint.h>
 
 #include <map>
 
 #include "ash/ash_export.h"
 #include "ash/common/wm_display_observer.h"
 #include "base/macros.h"
 #include "base/strings/string16.h"
 #include "ui/display/manager/managed_display_info.h"
@@ skipping 60 matching lines @@
   DisplayMode old_display_mode_ = DisplayMode::SINGLE;
   DisplayMode current_display_mode_ = DisplayMode::SINGLE;
 
   bool show_notifications_for_testing = true;
 
   DISALLOW_COPY_AND_ASSIGN(ScreenLayoutObserver);
 };
 
 }  // namespace ash
 
-#endif  // ASH_SYSTEM_CHROMEOS_SCREEN_LAYOUT_OBSERVER_H_
+#endif  // ASH_SYSTEM_SCREEN_LAYOUT_OBSERVER_H_