Mojo: adding a thread safe associated interface ptr.

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 4dc4b76538e6202964d329bd1582a0f91a1ea2e2..c2d40a95c586c35e8641e5093f0bd81d92f093eb 100644
--- a/mojo/public/cpp/bindings/lib/associated_interface_ptr_state.h
+++ b/mojo/public/cpp/bindings/lib/associated_interface_ptr_state.h
@@ -142,6 +142,13 @@ class AssociatedInterfacePtrState {
     return endpoint_client_ ? endpoint_client_->associated_group() : nullptr;
   }
 
+  void ForwardMessage(Message message) { endpoint_client_->Accept(&message); }
+
+  void ForwardMessageWithResponder(Message message,
+                                   std::unique_ptr<MessageReceiver> responder) {
+    endpoint_client_->AcceptWithResponder(&message, responder.release());
+  }
+
  private:
   using Proxy = typename Interface::Proxy_;