PNG_EXPORT_VAR    603 third_party/libpng/png.h PNG_EXPORT_VAR (PNG_CONST char) png_libpng_ver[18];
PNG_EXPORT_VAR   1517 third_party/libpng/pngconf.h #      define PNG_EXPORT_VAR(type) PNG_DATA_EXPORT
PNG_EXPORT_VAR   1528 third_party/libpng/pngconf.h #    define PNG_EXPORT_VAR(type) extern PNG_IMPEXP type