/usr/share/php/xajax/xajax_js/ is in php-xajax 0.5-1ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/php/xajax/xajax_js/xajax_core.js
/usr/share/php/xajax/xajax_js/xajax_core_uncompressed.js
/usr/share/php/xajax/xajax_js/xajax_debug.js
/usr/share/php/xajax/xajax_js/xajax_debug_uncompressed.js
/usr/share/php/xajax/xajax_js/xajax_lang_bg.js
/usr/share/php/xajax/xajax_js/xajax_lang_bg_uncompressed.js
/usr/share/php/xajax/xajax_js/xajax_lang_de.js
/usr/share/php/xajax/xajax_js/xajax_lang_de_uncompressed.js
/usr/share/php/xajax/xajax_js/xajax_lang_es.js
/usr/share/php/xajax/xajax_js/xajax_lang_es_uncompressed.js
/usr/share/php/xajax/xajax_js/xajax_lang_fr.js
/usr/share/php/xajax/xajax_js/xajax_lang_fr_uncompressed.js
/usr/share/php/xajax/xajax_js/xajax_lang_nl.js
/usr/share/php/xajax/xajax_js/xajax_lang_nl_uncompressed.js
/usr/share/php/xajax/xajax_js/xajax_lang_tr.js
/usr/share/php/xajax/xajax_js/xajax_lang_tr_uncompressed.js
/usr/share/php/xajax/xajax_js/xajax_legacy.js
/usr/share/php/xajax/xajax_js/xajax_legacy_uncompressed.js
/usr/share/php/xajax/xajax_js/xajax_verbose.js
/usr/share/php/xajax/xajax_js/xajax_verbose_uncompressed.js