Defer process mode upon draw

Process mode functor execution can be expensive, and cause dropped frames if it
runs between two expensive frames (when there isn't cpu time to spare). Avoid
this by delaying the process mode by an additional 4 ms every time we hit a draw

bug:7670326
Change-Id: I27f42458d4a815183a4b24c7748e05bc361fb943
1 file changed