Implement a MusBrowserFrame.

ui/views/mus/window_manager_connection.h

 // Copyright 2015 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 UI_VIEWS_MUS_WINDOW_MANAGER_CONNECTION_H_
 #define UI_VIEWS_MUS_WINDOW_MANAGER_CONNECTION_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "components/mus/public/cpp/window_tree_delegate.h"
 #include "components/mus/public/interfaces/window_manager.mojom.h"
@@ skipping 15 matching lines @@
 }
 
 // Establishes a connection to the window manager for use by views within an
 // application, and performs Aura initialization.
 class WindowManagerConnection : public mus::WindowTreeDelegate {
  public:
   static void Create(mus::mojom::WindowManagerPtr window_manager,
                      mojo::ApplicationImpl* app);
   static WindowManagerConnection* Get();
 
+  mojo::ApplicationImpl* app() { return app_; }
+
   mus::Window* NewWindow(const std::map<std::string,
                          std::vector<uint8_t>>& properties);
 
   mus::mojom::WindowManager* window_manager() {
     return window_manager_.get();
   }
 
  private:
   WindowManagerConnection(mus::mojom::WindowManagerPtr window_manager,
                           mojo::ApplicationImpl* app);
   ~WindowManagerConnection() override;
 
   // mus::WindowTreeDelegate:
   void OnEmbed(mus::Window* root) override;
   void OnConnectionLost(mus::WindowTreeConnection* connection) override;
 
   NativeWidget* CreateNativeWidget(internal::NativeWidgetDelegate* delegate);
 
   mojo::ApplicationImpl* app_;
   mus::mojom::WindowManagerPtr window_manager_;
   scoped_ptr<ui::mojo::UIInit> ui_init_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowManagerConnection);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_MUS_WINDOW_MANAGER_CONNECTION_H_