r phase with forwards fill is the active duration');

test(t => {
  const anim = createDiv(t).animate(null, { duration: 0,
                                            iterations: Infinity,
                                            fill: 'forwards' });
  anim.finish();
  assert_equals(anim.effect.getComputedTiming().currentIteration, Infinity);
  assert_equals(anim.effect.getComputedTiming().progress, 1);
}, 'Active time in after phase with forwards fill, zero-duration, and '
   + ' infinite iteration coun