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

components/html_viewer/ax_provider_apptest.cc

Index: components/html_viewer/ax_provider_apptest.cc
diff --git a/components/html_viewer/ax_provider_apptest.cc b/components/html_viewer/ax_provider_apptest.cc
index a8cd4e2a00a35b8fd588fcea869cfc461ae65f64..17d1c56319ebf6ae6c3b0954ee02f3aa4ca325d4 100644
--- a/components/html_viewer/ax_provider_apptest.cc
+++ b/components/html_viewer/ax_provider_apptest.cc
@@ -107,7 +107,7 @@ TEST_F(AXProviderTest, HelloWorld) {
   connection->ConnectToService(&frame_client);
   frame_client->OnConnect(
       std::move(frame_ptr), 1u, embed_window->id(),
-      web_view::mojom::WINDOW_CONNECT_TYPE_USE_NEW, std::move(array),
+      web_view::mojom::WindowConnectType::USE_NEW, std::move(array),
       base::TimeTicks::Now().ToInternalValue(), base::Closure());
 
   // Connect to the AxProvider of the HTML document and get the AxTree.