message: Prevent integer overflow in `OpLevelCostEstimator::CalculateTensorSize`.
  In order to not change the API, we return a negative value in case of overflow. A better fix is to change the API to return a status instead.
diff: @@ -1554,7 +1554,13 @@ int64 OpLevelCostEstimator::CalculateTensorSize(
  int64 count = CalculateTensorElementCount(tensor, found_unknown_shapes);
  int size = DataTypeSize(BaseType(tensor.dtype()));
  VLOG(2) << "Count: " << count << " DataTypeSize: " << size;
  - return count * size;
  + int64_t tensor_size = MultiplyWithoutOverflow(count, size);
  + if (tensor_size < 0) {
  + VLOG(1) << "Overflow encountered when computing tensor size, multiplying "
  + << count << " with " << size;
  + return -1;
  + }
  + return tensor_size;
  }
  int64 OpLevelCostEstimator::CalculateInputSize(const OpInfo& op_info,
  