ui.conf: ensure user 'chronos' processes all die
ui.conf: ensure user 'chronos' processes all die

Random user daemons that don't have ties to /home/chronos/user
are outliving the user session.  This is not safe!

This change just ensures that all user chronos processes are brought down.

TEST=test initctl stop ui; login; logout; log back in
BUG=none

Change-Id: I4bc60b96bd55712cf01df83e31fac36ab4a10877

Review URL: http://codereview.chromium.org/3583019

joshfire/chromiumos-platform-init