At the moment we only disarm the watchdog timer set up for SYNC counter
requests if we're in the middle of a resize operation.
It's possible that the resize operation finished prematurely by the user
letting go of the mouse before the client responded. If that happens, when the
client finally updates mutter will erroneously still have the watchdog timer
engaged from before until it times out, leading to resizes for the next second
or so to not get processed, and the client to get blacklisted from future sync
requests.
https://gitlab.gnome.org/GNOME/mutter/merge_requests/942
bac188b568