waitUntilPlayheadReachesOrFailOnTimeout(mediaElement, timeGoal, timeout) {
    this.timeoutAfter(timeout).failOnTimeout(true);
    return this.waitUntilPlayheadReaches(mediaElement, timeGoal);
  }
Wait for the video playhead to reach a certain target time.
If the playhead reaches |timeGoal| or the video ends before |timeout|
seconds pass, the Promise is resolved.
Otherwise, the Promise is rejected.
@param {!HTMLMediaElement} mediaElement
@param {number} timeGoal The time to wait for the playhead to reach.
@param {number} timeout Timeout in seconds, after which the Promise fails.
@return {!Promise}