Enable InputDeviceServer/InputDeviceClient in mash.

ash/sysui/sysui_application.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_SYSUI_SYSUI_APPLICATION_H_
 #define ASH_SYSUI_SYSUI_APPLICATION_H_
 
 #include <memory>
 
 #include "ash/sysui/public/interfaces/wallpaper.mojom.h"
 #include "base/macros.h"
+#include "components/mus/public/cpp/input_devices/input_device_client.h"
 #include "mash/shelf/public/interfaces/shelf.mojom.h"
 #include "mojo/public/cpp/bindings/binding_set.h"
 #include "services/shell/public/cpp/shell_client.h"
 #include "services/tracing/public/cpp/tracing_impl.h"
 
 namespace ash {
 namespace sysui {
 
 class AshInit;
 
@@ skipping 20 matching lines @@
   void Create(shell::Connection* connection,
               mojom::WallpaperControllerRequest request) override;
 
   mojo::TracingImpl tracing_;
   std::unique_ptr<AshInit> ash_init_;
 
   mojo::BindingSet<mash::shelf::mojom::ShelfController>
       shelf_controller_bindings_;
   mojo::BindingSet<mojom::WallpaperController> wallpaper_controller_bindings_;
 
+  // Subscribes to updates about input-devices.
+  ::mus::InputDeviceClient input_device_client_;
+
   DISALLOW_COPY_AND_ASSIGN(SysUIApplication);
 };
 
 }  // namespace sysui
 }  // namespace ash
 
 #endif  // ASH_SYSUI_SYSUI_APPLICATION_H_