1 Tests that overflow scrolls on the root frame are animated.
3 On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
6 PASS window.scrollY is not document.body.scrollHeight - window.innerHeight
7 PASS window.scrollY is > 0
8 PASS window.scrollY is > prevScrollY
9 PASS successfullyParsed is true