Mojo: introducing a thread safe interface pointer.

mojo/public/cpp/bindings/lib/associated_interface_ptr_state.h

Index: mojo/public/cpp/bindings/lib/associated_interface_ptr_state.h
diff --git a/mojo/public/cpp/bindings/lib/associated_interface_ptr_state.h b/mojo/public/cpp/bindings/lib/associated_interface_ptr_state.h
index 7128a908d9dbacb5efd5d93b1d3d2aa8d74195b7..4dc4b76538e6202964d329bd1582a0f91a1ea2e2 100644
--- a/mojo/public/cpp/bindings/lib/associated_interface_ptr_state.h
+++ b/mojo/public/cpp/bindings/lib/associated_interface_ptr_state.h
@@ -103,8 +103,7 @@ class AssociatedInterfacePtrState {
         std::move(runner), 0u));
     proxy_.reset(new Proxy(endpoint_client_.get()));
     if (Interface::PassesAssociatedKinds_) {
-      proxy_->serialization_context()->group_controller =
-          endpoint_client_->group_controller();
+      proxy_->set_group_controller(endpoint_client_->group_controller());
     }
   }