message: Fix NV21 -> RGB conversion bug.
diff: @@ -139,7 +139,7 @@ absl::Status ConvertFromNv21(const FrameBuffer& buffer,
  // the big endian style with R being the first byte in memory.
  int ret = libyuv::NV21ToRAW(
  yuv_data.y_buffer, yuv_data.y_row_stride, yuv_data.v_buffer,
  - yuv_data.uv_pixel_stride,
  + yuv_data.uv_row_stride,
  const_cast<uint8*>(output_buffer->plane(0).buffer),
  output_buffer->plane(0).stride.row_stride_bytes,
  buffer.dimension().width, buffer.dimension().height);
  