 endDelay: -4000,
                                            fill: 'forwards' });
  anim.finish();
  assert_equals(anim.effect.getComputedTiming().currentIteration, 0);
  assert_equals(anim.effect.getComputedTiming().progress, 0);
}, 'Active time in after phase with forwards fill and negative end delay'
   + ' greater in magnitude than the sum of the active duration and start delay'
   + ' is zero');

test(t => {
  const anim = createDiv(t).animate(null, { duration: 1000,
                                  