Comment 2 for bug 1576454

I think both files come from Debian. I did an 'apt-get source x11-common' and I see that debian/x11-common.install installs stuff from debian/local/Xsession.d. I see both files there:

stefan@spuiu-vm:~/src/ubuntu/xorg-7.7+19ubuntu14$ grep -rn xhost debian/local/Xsession.d/
debian/local/Xsession.d/35x11-common_xhost-local:3:# If xhost (from x11-xserver-utils) is installed, use it to give access
debian/local/Xsession.d/35x11-common_xhost-local:5:# Unlike other uses of xhost, this is safe since the kernel can check
debian/local/Xsession.d/35x11-common_xhost-local:8:if type xhost >/dev/null 2>&1; then
debian/local/Xsession.d/35x11-common_xhost-local:9: xhost +si:localuser:$(id -un) || :
debian/local/Xsession.d/60x11-common_localhost:3:[ -x /usr/bin/xhost ] && [ -x /usr/bin/id ] &&
debian/local/Xsession.d/60x11-common_localhost:4: xhost +si:localuser:`id -un` > /dev/null