scroll() on a non-scroll-container: scrollLeft=0 scrollTop=0
scrollBy() on a non-scroll-container: scrollLeft=0 scrollTop=0
scrollLeft/scrollTop on a non-scroll-container: scrollLeft=0 scrollTop=0
scroll events on a non-scroll-container: 0
scrollend events on a non-scroll-container: 0
after becoming a scroll container: scrollLeft=0 scrollTop=0
scroll() on a scroll container: scrollLeft=40 scrollTop=50
after ceasing to be a scroll container: scrollLeft=0 scrollTop=0
after scrolling while not a scroll container: scrollLeft=0 scrollTop=0
after becoming a scroll container again: scrollLeft=40 scrollTop=50
