message: Add VLOG for optimizer return status.
diff: @@ -134,6 +134,8 @@ Status MetaOptimizer::Optimize(Cluster* cluster, const GrapplerItem& item,
  ". Graph size after: ", optimized_graph->node_size());
  }
  result_.push_back(std::make_pair(optimizer->name(), result));
  + VLOG(1) << "Optimizer " << optimizer->name()
  + << " return status: " << result;
  } else {
  GrapplerItem optimized_item(item, std::move(*optimized_graph));
  auto status =
  @@ -152,6 +154,8 @@ Status MetaOptimizer::Optimize(Cluster* cluster, const GrapplerItem& item,
  ". Graph size after: ", optimized_graph->node_size());
  }
  result_.push_back(std::make_pair(optimizer->name(), result));
  + VLOG(1) << "Optimizer " << optimizer->name()
  + << " return status: " << result;
  }
  }
  