Normally we expect timer creation/initialization to be infallible, but there appear to be rare cases where it fails.
It would be good to understand the cause, but first of all we should honor the return value in case of error.
Note that allocations during timer init are infallible since bug 1961386, so most likely the cause is not running low on memory.
Original Revision: https://phabricator.services.mozilla.com/D262593
Differential Revision: https://phabricator.services.mozilla.com/D266578