Bug 284548

The WPT test scroll-animations/scroll-timelines/setting-timeline.tentative.html has 5 failures: FAIL Setting a scroll timeline on a running animation synchronizes the currentTime of the animation with the scroll position. assert_approx_equals: Timeline's currentTime aligns with the scroll position even when paused expected a number but got a "object" FAIL Switching from a null timeline to a scroll timeline on an animation with a resolved start time preserved the play state promise_test: Unhandled rejection with value: object "TypeError: null is not an object (evaluating 'actual.unit')" FAIL Switching from one scroll timeline to another updates currentTime promise_test: Unhandled rejection with value: object "TypeError: null is not an object (evaluating 'actual.unit')" FAIL Switching from a document timeline to a scroll timeline on an infinite duration animation. assert_approx_equals: values do not match for "undefined" expected 100 +/- 0.125 but got 200 FAIL Changing from a scroll-timeline to a view-timeline updates start time. promise_test: Unhandled rejection with value: object "TypeError: null is not an object (evaluating 'actual.unit')"