Bug 1415780 - Call UpdateTiming() prior to remove the animtion from the timeline in Animation::CancelNoUpdate. r=birtles

Now AnimationEventDispatcher ensures that the refresh driver's next tick
happens for cancel event, so we don't need to re-observe the timeline
(it happens in UpdateTiming) once after removing the animation from the
timeline.

MozReview-Commit-ID: 7ivclmYIkPa

--HG--
extra : rebase_source : 286b3d5d29208496bfe8405819b44b5f52f6671c

dom/animation/Animation.cpp

@@ -804,21 +804,12 @@ Animation::CancelNoUpdate()
   mHoldTime.SetNull();
   mStartTime.SetNull();
 
+  UpdateTiming(SeekFlag::NoSeek, SyncNotifyFlag::Async);
+
   if (mTimeline) {
     mTimeline->RemoveAnimation(this);
   }
   MaybeQueueCancelEvent(activeTime);
-
-  // When an animation is cancelled it no longer needs further ticks from the
-  // timeline. However, if we queued a cancel event and this was the last
-  // animation attached to the timeline, the timeline will stop observing the
-  // refresh driver and there may be no subsequent refresh driver tick for
-  // dispatching the queued event.
-  //
-  // By calling UpdateTiming *after* removing ourselves from our timeline, we
-  // ensure the timeline will register with the refresh driver for at least one
-  // more tick.
-  UpdateTiming(SeekFlag::NoSeek, SyncNotifyFlag::Async);
 }
 
 bool