/usr/lib/firefox/ is in firefox-locale-ta 28.0+build2-0ubuntu2.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/firefox-addons/extensions/
/usr/lib/firefox-addons/extensions/langpack-ta@firefox.mozilla.org.xpi
/usr/lib/firefox/distribution/
/usr/lib/firefox/distribution/searchplugins/
/usr/lib/firefox/distribution/searchplugins/locale/
/usr/lib/firefox/distribution/searchplugins/locale/ta/
/usr/lib/firefox/distribution/searchplugins/locale/ta/creativecommons.xml
/usr/lib/firefox/distribution/searchplugins/locale/ta/duckduckgo.xml
/usr/lib/firefox/distribution/searchplugins/locale/ta/eBay-in.xml
/usr/lib/firefox/distribution/searchplugins/locale/ta/google.xml
/usr/lib/firefox/distribution/searchplugins/locale/ta/wikipedia-ta.xml
/usr/lib/firefox/distribution/searchplugins/locale/ta/yahoo-in.xml