message: Remove attribute _output_shapes to reduce the graph size.
diff: @@ -1138,6 +1138,7 @@ class DataLayoutOptimizer {
  std::unordered_set<string> nodes_removable;
  for (int i = 0; i < graph_->node_size(); i++) {
  auto node = graph_->mutable_node(i);
  + node->mutable_attr()->erase("_output_shapes");
  if (IsNodeNHWCToNCHW(node->name())) {
  if (IsNodeNCHWToNHWC(node->input(0))) {
  const string& trans_first = node->input(0);
  