/usr/ is in xul-ext-livehttpheaders 0.17-3.
This file is owned by root:root, with mode 0o755.
..
/usr/share/
/usr/share/mozilla/
/usr/share/mozilla/extensions/
/usr/share/mozilla/extensions/{92650c4d-4b8e-4d2a-b7eb-24ecf4f6b63a}/
/usr/share/mozilla/extensions/{a463f10c-3994-11da-9945-000d60ca027b}/
/usr/share/mozilla/extensions/{ec8030f7-c20a-464f-9b0e-13a3a9e97384}/
/usr/share/xul-ext/
/usr/share/xul-ext/livehttpheaders/
/usr/share/xul-ext/livehttpheaders/install.rdf
/usr/share/xul-ext/livehttpheaders/TODO.txt
/usr/share/xul-ext/livehttpheaders/install.js
/usr/share/xul-ext/livehttpheaders/chrome/
/usr/share/xul-ext/livehttpheaders/chrome/icons/
/usr/share/xul-ext/livehttpheaders/chrome/icons/default/
/usr/share/xul-ext/livehttpheaders/chrome/icons/default/LiveHTTPHeaders.ico
/usr/share/xul-ext/livehttpheaders/chrome/icons/default/LiveHTTPHeaders.xpm
/usr/share/xul-ext/livehttpheaders/chrome/livehttpheaders.jar
/usr/share/xul-ext/livehttpheaders/defaults/
/usr/share/xul-ext/livehttpheaders/defaults/preferences/
/usr/share/xul-ext/livehttpheaders/defaults/preferences/prefs.js
/usr/share/xul-ext/livehttpheaders/chrome.manifest
/usr/share/xul-ext/livehttpheaders/components/
/usr/share/xul-ext/livehttpheaders/components/nsHeaderInfo.js
/usr/share/doc/
/usr/share/doc/xul-ext-livehttpheaders/
/usr/share/doc/xul-ext-livehttpheaders/changelog.Debian.gz
/usr/share/doc/xul-ext-livehttpheaders/copyright
/usr/share/mozilla/extensions/{92650c4d-4b8e-4d2a-b7eb-24ecf4f6b63a}/{8f8fe09b-0bd3-4470-bc1b-8cad42b8203a}
/usr/share/mozilla/extensions/{a463f10c-3994-11da-9945-000d60ca027b}/{8f8fe09b-0bd3-4470-bc1b-8cad42b8203a}
/usr/share/mozilla/extensions/{ec8030f7-c20a-464f-9b0e-13a3a9e97384}/{8f8fe09b-0bd3-4470-bc1b-8cad42b8203a}
/usr/share/xul-ext/livehttpheaders/defaults/preferences/000system.js