Change mojo enums to be scoped enums in the generated C++ bindings.

mash/shelf/shelf_application.cc

Index: mash/shelf/shelf_application.cc
diff --git a/mash/shelf/shelf_application.cc b/mash/shelf/shelf_application.cc
index 46569780467e2bb475a57cee8a7fc0f035f9e4b4..cb829fe362e7c7457e08698b6db8ae52f4dd772d 100644
--- a/mash/shelf/shelf_application.cc
+++ b/mash/shelf/shelf_application.cc
@@ -35,11 +35,11 @@ void ShelfApplication::Initialize(mojo::ApplicationImpl* app) {
   std::map<std::string, std::vector<uint8_t>> properties;
   properties[mash::wm::mojom::kWindowContainer_Property] =
       mojo::TypeConverter<const std::vector<uint8_t>, int32_t>::Convert(
-          mash::wm::mojom::CONTAINER_USER_SHELF);
+          static_cast<int32_t>(mash::wm::mojom::Container::USER_SHELF));
   mus::Window* window =
       views::WindowManagerConnection::Get()->NewWindow(properties);
   params.native_widget = new views::NativeWidgetMus(
-      widget, app->shell(), window, mus::mojom::SURFACE_TYPE_DEFAULT);
+      widget, app->shell(), window, mus::mojom::SurfaceType::DEFAULT);
   widget->Init(params);
   widget->Show();
 }