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

ash/mus/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_MUS_SYSUI_APPLICATION_H_
+#define ASH_MUS_SYSUI_APPLICATION_H_
+
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "mojo/services/tracing/public/cpp/tracing_impl.h"
+#include "mojo/shell/public/cpp/shell_client.h"
+
+namespace ash {
+namespace sysui {
+
+class AshInit;
+
+class SysUIApplication : public mojo::ShellClient {
+ public:
+  SysUIApplication();
+  ~SysUIApplication() override;
+
+ private:
+  // mojo::ShellClient:
+  void Initialize(mojo::Shell* shell,
+                  const std::string& url,
+                  uint32_t id) override;
+
+  mojo::TracingImpl tracing_;
+  scoped_ptr<AshInit> ash_init_;
+
+  DISALLOW_COPY_AND_ASSIGN(SysUIApplication);
+};
+
+}  // namespace sysui
+}  // namespace ash
+
+#endif  // ASH_MUS_SYSUI_APPLICATION_H_