message: Do not try to implement GradGrad on 3D pooling
diff: @@ -37,6 +37,7 @@ static bool OpFilter(KernelDef* kdef) {
  if (kdef->op() == "IFFT3D") return false;
  if (kdef->op() == "Imag") return false;
  if (kdef->op() == "MaxPoolGradGrad") return false;
  + if (kdef->op() == "MaxPool3DGradGrad") return false;
  if (kdef->op() == "Real") return false;
  return true;
  