yncRefs.push(animationFrame.run(callback));
    asyncRefs.push(animationFrame.run(callback));
    asyncRefs.push(animationFrame.run(callback));
    animationFrame.cancel(asyncRefs.pop());
    animationFrame.cancel(asyncRefs.pop());
    animationFrame.cancel(asyncRefs.pop());
    requestAnimationFrame(function() {
      assert.isFalse(callback.called);
      done();
    });
  });

  test('Multiple queued functions are individually cancelable.', function(done) {
    var callback1 = sinon.spy();
    var callba