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

ash/system/toast/toast_overlay.h

 // Copyright 2016 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_TOAST_TOAST_OVERLAY_H_
-#define ASH_COMMON_SYSTEM_TOAST_TOAST_OVERLAY_H_
+#ifndef ASH_SYSTEM_TOAST_TOAST_OVERLAY_H_
+#define ASH_SYSTEM_TOAST_TOAST_OVERLAY_H_
 
 #include <memory>
 
 #include "ash/ash_export.h"
 #include "base/optional.h"
 #include "base/strings/string16.h"
 #include "ui/compositor/layer_animation_observer.h"
 #include "ui/events/event.h"
 #include "ui/events/event_constants.h"
 #include "ui/gfx/geometry/size.h"
@@ skipping 52 matching lines @@
   const base::Optional<base::string16> dismiss_text_;
   std::unique_ptr<views::Widget> overlay_widget_;
   std::unique_ptr<ToastOverlayView> overlay_view_;
   gfx::Size widget_size_;
 
   DISALLOW_COPY_AND_ASSIGN(ToastOverlay);
 };
 
 }  // namespace ash
 
-#endif  // ASH_COMMON_SYSTEM_TOAST_TOAST_OVERLAY_H_
+#endif  // ASH_SYSTEM_TOAST_TOAST_OVERLAY_H_