mash: Migrate ShellDelegate ownership and access to WmShell.

ash/common/shell_delegate.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_SHELL_DELEGATE_H_
-#define ASH_SHELL_DELEGATE_H_
+#ifndef ASH_COMMON_SHELL_DELEGATE_H_
+#define ASH_COMMON_SHELL_DELEGATE_H_
 
 #include <memory>
 #include <string>
 
 #include "ash/ash_export.h"
 #include "base/callback.h"
 #include "base/strings/string16.h"
 
 class GURL;
 
@@ skipping 142 matching lines @@
 
   virtual gfx::Image GetDeprecatedAcceleratorImage() const = 0;
 
   // Toggles the status of the touchpad / touchscreen on or off.
   virtual void ToggleTouchpad() {}
   virtual void ToggleTouchscreen() {}
 };
 
 }  // namespace ash
 
-#endif  // ASH_SHELL_DELEGATE_H_
+#endif  // ASH_COMMON_SHELL_DELEGATE_H_