[ubuntu] 16.04 - Changes in /usr/share/X11/xkb/symbols/* have no effect

I have modified /usr/share/X11/xkb/symbols/us but the changes are not taking effect. In the previous versions, I would remove /var/lib/xkb/*.xkm and reboot, then it would work. But with Ubuntu 16.04 there are no *.xkm files under /var/lib/xkb to delete. Is there a change of keyboard layout caching mechanism in 16.04?

Also, 'man setkxbmap' retus ' no manual for setkxbmap'. This manual was the source of information on where are the cached layout.