/usr/share/frei0r/html/files.js is in frei0r-plugins-doc 1.4-3build1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4
var files = [ [ "frei0r.h", "frei0r_8h.html", "frei0r_8h" ] ];