message: Assert that gRPC calls do not exceed the 2GB protobuf size limit.
diff: @@ -140,6 +140,15 @@ static void EncodeSkeleton(const Tensor& val, io::ProtoEncodeHelper* e) {
  void EncodeTensorToByteBuffer(bool is_dead, const Tensor& val, bool require_ack,
  ::grpc::ByteBuffer* result) {
  const int kLargeTensorBytes = 1024;
  + const int64 kProtoBufLimitBytes = 1LL << 31;
  +
  + if (val.TotalBytes() > kProtoBufLimitBytes) {
  + size_t exceeded_bytes = val.TotalBytes() - kProtoBufLimitBytes;
  + LOG(FATAL) << "Cannot encode a Tensor that exceeds the 2GB protobuf limit. "
  + "Exceeded bytes: "
  + << exceeded_bytes;
  + }
  +
  RecvTensorResponse response;
  if (is_dead) {
  response.set_is_dead(is_dead);
  