Non Composited Scroller In Scrolled Position Fixed Scroller

This turquoise box is a position: fixed scroller. The black-and-white scroller beelow has a clip region so should be non-composited.

Scroll the turquoise box so the black-and-white scroller appears near its top edge. Now attempt to scroll over the black-and-white scroller with wheel or touch. If the box scrolls, the test passes. This turquoise scroller must not scroll.