Comment 30 for bug 1574120

Affects HP Spectre z360 also (suspend works from interface but does not happen when lid closed despite setting in power settings) - had to both upgrade to kernel 4.4.8 from 4.4.0 and add the workarounds to /etc/systemd/login.d to get it to work - just upgrade / workaround did not work separately. No multiple displays or dock (xrandr confirmed) - but haven't checked if power connecter removed works without workaround (not any use to me).

systemd-inhibit output -
     Who: sam (UID 1000/sam, PID 1750/unity-settings-)
    What: handle-power-key:handle-suspend-key:handle-hibernate-key
     Why: GNOME handling keypresses
    Mode: block

     Who: sam (UID 1000/sam, PID 1750/unity-settings-)
    What: sleep
     Why: GNOME needs to lock the screen
    Mode: delay

     Who: NetworkManager (UID 0/root, PID 873/NetworkManager)
    What: sleep
     Why: NetworkManager needs to turn off networks
    Mode: delay

     Who: sam (UID 1000/sam, PID 1757/gnome-session-b)
    What: shutdown:sleep
     Why: user session inhibited
    Mode: block

4 inhibitors listed.