ement
    assert_equals(document.scrollingElement, null,
                  "In quirks, we would expect null here (because of potentially scrollable body)");
}, "scrollingElement in quirks should be null when body is potentially scrollable.")

test(function() {
    document.documentElement.style.overflowY = "visible";
    assert_equals(document.documentElement.style.overflowY, "visible");
    assert_equals(document.scrollingElement, document.body);

    document.documentElement.style.overflowY = "scroll";
  