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

mandoline/ui/omnibox/omnibox_application.cc

Index: mandoline/ui/omnibox/omnibox_application.cc
diff --git a/mandoline/ui/omnibox/omnibox_application.cc b/mandoline/ui/omnibox/omnibox_application.cc
index dec5c76adf2158f70233b338abd9b30eb089683c..0479f4ac0660ee5096e06da00b815c79142a0ec7 100644
--- a/mandoline/ui/omnibox/omnibox_application.cc
+++ b/mandoline/ui/omnibox/omnibox_application.cc
@@ -144,7 +144,7 @@ void OmniboxImpl::OnEmbed(mus::Window* root) {
   views::Widget::InitParams params(
       views::Widget::InitParams::TYPE_WINDOW_FRAMELESS);
   params.native_widget = new views::NativeWidgetMus(
-      widget, app_->shell(), root, mus::mojom::SURFACE_TYPE_DEFAULT);
+      widget, app_->shell(), root, mus::mojom::SurfaceType::DEFAULT);
   params.delegate = widget_delegate;
   params.bounds = root->bounds();
   params.opacity = views::Widget::InitParams::TRANSLUCENT_WINDOW;