switching workspaces sometimes crashes system on macbook
I'm running 16.04 on a MacBookPro10,1 but I have also seen this running 15.10 on the same system
I have keybinds to change workspaces with cntrl+opt and arrow left/right. After working on the system for a while (2-4+ hours) regularly switching spaces the system will crash. This mostly happens on a switch left.
Description of crash: Display goes black, audio dies, fan and keyboard lights are still running and cntrl+alt+F1 does nothing. I need to hold power to kill the system and boot up again.