t.animate([{top: '0px'}, {top: '1000px'}], 10);
  at(1, function() {
    assert_styles(element, {top: '100px'});

    player.source.timing.delay = -1;
    assert_styles(element, {top: '200px'});
  });
}, 'Updated style should be visible after change to specified timing');

var group = new AnimationSequence([
  new Animation(element, {}, 1),
  new Animation(element, [{right: '0px'}, {right: '1000px'}], 10),
]);
document.timeline.play(group);
timing_test(function() {
  at(2, function() {
    assert_styles(ele