/etc/xul-ext/mozilla-biofox.js is in mozilla-biofox 1.6-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 | // Place your preferences for mozilla-biofox in this file.
// You can override here the preferences specified in
// /usr/share/xul-ext/mozilla-biofox/defaults/preferences/prefs.js
|