Test for rdar://problem/6643103 Unscaled values from body.scrollHeight.

scrollHeight: 1000
scrollWidth: 1000

Scrolling right to 50
scrollLeft: 50

Zooming in
scrollHeight: 1000
scrollWidth: 1000
scrollTop: 0
scrollLeft: 50

Scrolling down to 100
scrollTop: 100

Zooming back out
scrollTop: 100
scrollLeft: 50