Require an explicit ServiceName annotation for interfaces in C++.

mojo/services/ui/views/interfaces/view_manager.mojom

Index: mojo/services/ui/views/interfaces/view_manager.mojom
diff --git a/mojo/services/ui/views/interfaces/view_manager.mojom b/mojo/services/ui/views/interfaces/view_manager.mojom
index 0e45fe661cd45f5a83ae8f8364e1195e6f8aac1e..febf24acc0e303518bb1a8fb639b47c71c041270 100644
--- a/mojo/services/ui/views/interfaces/view_manager.mojom
+++ b/mojo/services/ui/views/interfaces/view_manager.mojom
@@ -13,6 +13,7 @@ import "mojo/services/ui/views/interfaces/view_trees.mojom";
 // Before a view can be added to the view tree, it must first be registered
 // with the view manager.  Once registered, the view receives a token as a
 // transferable reference to be provided to the view's intended container.
+[ServiceName="mojo::ui::ViewManager"]
 interface ViewManager {
   // Registers a view with the view manager.
   //