message: Add int8 support in AddTensor.
diff: @@ -307,10 +307,12 @@ class SingleOpModel {
  if (is_quantized) {
  if (t.min != 0 || t.max != 0) {
  - // TODO(b/119422369): Handle signed int8 here.
  if (t.type == TensorType_UINT8) {
  std::tie(t.scale, t.zero_point) =
  QuantizationParams<uint8_t>(t.min, t.max);
  + } else if (t.type == TensorType_INT8) {
  + std::tie(t.scale, t.zero_point) =
  + QuantizationParams<int8_t>(t.min, t.max);
  } else if (t.type == TensorType_INT32) {
  std::tie(t.scale, t.zero_point) =
  QuantizationParams<int32_t>(t.min, t.max);
  