/usr/lib/ is in firefox-locale-ro 11.0+build1-0ubuntu4.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/firefox-addons/
/usr/lib/firefox-addons/extensions/
/usr/lib/firefox-addons/extensions/langpack-ro@firefox.mozilla.org.xpi
/usr/lib/firefox/
/usr/lib/firefox/distribution/
/usr/lib/firefox/distribution/searchplugins/
/usr/lib/firefox/distribution/searchplugins/locale/
/usr/lib/firefox/distribution/searchplugins/locale/ro/
/usr/lib/firefox/distribution/searchplugins/locale/ro/amazondotcom.xml
/usr/lib/firefox/distribution/searchplugins/locale/ro/bing.xml
/usr/lib/firefox/distribution/searchplugins/locale/ro/eBay.xml
/usr/lib/firefox/distribution/searchplugins/locale/ro/google.xml
/usr/lib/firefox/distribution/searchplugins/locale/ro/wikipediaro.xml
/usr/lib/firefox/distribution/searchplugins/locale/ro/yahoo.xml