ash/mash: Add a mus-client that sets up ash to provide the system ui for mash.

ash/root_window_settings.h

 // Copyright 2013 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_ROOT_WINDOW_SETTINGS_H_
 #define ASH_ROOT_WINDOW_SETTINGS_H_
 
 #include <stdint.h>
 
 #include "ash/ash_export.h"
@@ skipping 15 matching lines @@
   // ID of the display associated with the root window.
   int64_t display_id;
 
   // RootWindowController for the root window. This may be NULL
   // for the root window used for mirroring.
   RootWindowController* controller;
 };
 
 // Initializes and returns RootWindowSettings for |root|.
 // It is owned by the |root|.
-RootWindowSettings* InitRootWindowSettings(aura::Window* root);
+ASH_EXPORT RootWindowSettings* InitRootWindowSettings(aura::Window* root);
 
 // Returns the RootWindowSettings for |root|.
 ASH_EXPORT RootWindowSettings* GetRootWindowSettings(aura::Window* root);
 
 // const version of GetRootWindowSettings.
 ASH_EXPORT const RootWindowSettings*
 GetRootWindowSettings(const aura::Window* root);
 
 }  // namespace ash
 
 #endif  // ASH_ROOT_WINDOW_SETTINGS_H_