PNG_INFO_IDAT     597 third_party/libpng/png.c       info_ptr->valid &= ~PNG_INFO_IDAT;
PNG_INFO_IDAT    1517 third_party/libpng/pngread.c    info_ptr->valid |= PNG_INFO_IDAT;
PNG_INFO_IDAT    1143 third_party/libpng/pngset.c       info_ptr->valid |= PNG_INFO_IDAT;
PNG_INFO_IDAT    1583 third_party/libpng/pngwrite.c    if (info_ptr->valid & PNG_INFO_IDAT)