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

ui/views/mus/window_manager_connection.cc

Index: ui/views/mus/window_manager_connection.cc
diff --git a/ui/views/mus/window_manager_connection.cc b/ui/views/mus/window_manager_connection.cc
index 49ddec69b3b0168ca7ad3ccb25ca61f74a541416..5436f6abce87e5e77096c410484c29e9dc107659 100644
--- a/ui/views/mus/window_manager_connection.cc
+++ b/ui/views/mus/window_manager_connection.cc
@@ -48,6 +48,15 @@ mus::Window* WindowManagerConnection::NewWindow(
   return window_tree_connection_->NewTopLevelWindow(&properties);
 }
 
+NativeWidget* WindowManagerConnection::CreateNativeWidgetMus(
+    const Widget::InitParams& init_params,
+    internal::NativeWidgetDelegate* delegate) {
+  std::map<std::string, std::vector<uint8_t>> properties;
+  NativeWidgetMus::ConfigurePropertiesForNewWindow(init_params, &properties);
+  return new NativeWidgetMus(delegate, app_->shell(), NewWindow(properties),
+                             mus::mojom::SurfaceType::DEFAULT);
+}
+
 WindowManagerConnection::WindowManagerConnection(mojo::ApplicationImpl* app)
     : app_(app), window_tree_connection_(nullptr) {
   window_tree_connection_.reset(mus::WindowTreeConnection::Create(this, app_));
@@ -55,9 +64,8 @@ WindowManagerConnection::WindowManagerConnection(mojo::ApplicationImpl* app)
   screen_.reset(new ScreenMus(this));
   screen_->Init(app);
 
-  ViewsDelegate::GetInstance()->set_native_widget_factory(
-      base::Bind(&WindowManagerConnection::CreateNativeWidget,
-                 base::Unretained(this)));
+  ViewsDelegate::GetInstance()->set_native_widget_factory(base::Bind(
+      &WindowManagerConnection::CreateNativeWidgetMus, base::Unretained(this)));
 }
 
 WindowManagerConnection::~WindowManagerConnection() {
@@ -76,13 +84,4 @@ void WindowManagerConnection::OnWindowManagerFrameValuesChanged() {
     NativeWidgetMus::NotifyFrameChanged(window_tree_connection_.get());
 }
 
-NativeWidget* WindowManagerConnection::CreateNativeWidget(
-    const Widget::InitParams& init_params,
-    internal::NativeWidgetDelegate* delegate) {
-  std::map<std::string, std::vector<uint8_t>> properties;
-  NativeWidgetMus::ConfigurePropertiesForNewWindow(init_params, &properties);
-  return new NativeWidgetMus(delegate, app_->shell(), NewWindow(properties),
-                             mus::mojom::SurfaceType::DEFAULT);
-}
-
 }  // namespace views