DOMTimers sometimes don't get unthrottled on scrolling. This is because we stop listening for viewport changes every time the timer fires, but we don't listen for those changes again if we decide the timer should stay throttled after the timer's action was executed. We should listen for viewport changes again after executing the action, if there are elements outside the viewport causing the DOMTimer to be throttled, even if the throttleState hasn't changed.
Created attachment 241801 [details] Patch
Comment on attachment 241801 [details] Patch Thanks for reviewing quickly.
Comment on attachment 241801 [details] Patch Clearing flags on attachment: 241801 Committed r176282: <http://trac.webkit.org/changeset/176282>
All reviewed patches have been landed. Closing bug.