Mojo C++ bindings: sync call support for associated interfaces and master interfaces

mojo/public/cpp/bindings/associated_binding.h

Index: mojo/public/cpp/bindings/associated_binding.h
diff --git a/mojo/public/cpp/bindings/associated_binding.h b/mojo/public/cpp/bindings/associated_binding.h
index 37f22bdbc327bbd272847285a1a49a3f97a0c966..a7263635fef1f27e95add09fd08e37e2f312b4a0 100644
--- a/mojo/public/cpp/bindings/associated_binding.h
+++ b/mojo/public/cpp/bindings/associated_binding.h
@@ -80,7 +80,8 @@ class AssociatedBinding {
 
     endpoint_client_.reset(new internal::InterfaceEndpointClient(
         std::move(handle), &stub_,
-        make_scoped_ptr(new typename Interface::RequestValidator_())));
+        make_scoped_ptr(new typename Interface::RequestValidator_()),
+        Interface::HasSyncMethods_));
     endpoint_client_->set_connection_error_handler(
         [this]() { connection_error_handler_.Run(); });