[snapchanging-on-user-scroll.tentative.html]
expected: TIMEOUT
[touch scrolling fires snapchanging.]
expected: FAIL
[mouse wheel scroll triggers snapchanging.]
expected: FAIL
[scrollbar dragging fires snapchanging.]
expected: FAIL
[keyboard scroll triggers snapchanging.]
expected: FAIL
[snapchanging fires as scroll moves through different snap targets.]
expected: TIMEOUT
[snapchanging doesn't fire if scroll doesn't reach different snap targets.]
expected: NOTRUN