message: make op_level_cost_estimator more robust with "random" input part 2
diff: @@ -1871,6 +1871,7 @@ Costs OpLevelCostEstimator::PredictMaxPoolGrad(
  // x: op_info.inputs(0)
  // y: op_info.inputs(1)
  // y_grad: op_info.inputs(2)
  + if (op_info.inputs_size() < 3) return Costs::ZeroCosts(/*inaccurate=*/true);
  ConvolutionDimensions dims = OpDimensionsFromInputs(
  op_info.inputs(0).shape(), op_info, &found_unknown_shapes);
  