servo: Merge #8591 - Correct undisciplined rebase. (Closes #8583.) (from benschulz:im-a-toddler); r=jdm

I screwed up the rebase on top of #8175; sorry to waste your time with this, @jdm. :(

Source-Repo: https://github.com/servo/servo
Source-Revision: d11442bdcccf4002cdb84e85fe726130047a2b07

servo/components/script/timers.rs

@@ -194,8 +194,6 @@ impl ActiveTimers {
                                   duration: MsDuration,
                                   is_interval: IsInterval,
                                   source: TimerSource) -> TimerHandle {
-        assert!(self.suspended_since.get().is_none());
-
         // step 3
         let TimerHandle(new_handle) = self.next_timer_handle.get();
         self.next_timer_handle.set(TimerHandle(new_handle + 1));