Virtually they removed it in 68 with setting the flag when any of the files was present. Unfortunately they also changed the css model, so even with the flag o

Virtually they removed it in 68 with setting the flag when any of the files was present. Unfortunately they also changed the css model, so even with the flag on - userChrome.css has become useless (to me)... I guess 66 will not be seeing an upgrade for the time being. As for the question - should be less than 1ms (depends on the OS/filesystem obviously but still negligible)