message: Don't try to feed placeholder with default. Instead we rely on the default
  value.
diff: @@ -297,7 +297,7 @@ std::unique_ptr<GrapplerItem> GrapplerItemFromMetaGraphDef(
  }
  for (auto& node : *new_item->graph.mutable_node()) {
  - if (IsPlaceholder(node)) {
  + if (IsPlaceholder(node) && node.op() != "PlaceholderWithDefault") {
  if (node.attr().count("dtype") == 0) {
  LOG(ERROR) << "Unknown type for placeholder " << node.name()
  << ", skipping this input";
  