Flat Tree will be: DIV id=sandbox DIV id=top DIV id=shadow-host #text Moving mouse from a direct child text node of the shadow root to top mouseout @shadow-host (target: shadow-host) (related: top) @top (target: shadow-host) (related: top) mouseover @top (target: top) (related: shadow-host) touchstart @shadow-host (target: shadow-host) (touches: shadow-host) (targetTouches: shadow-host) (changedTouches: shadow-host) @top (target: shadow-host) (touches: shadow-host) (targetTouches: shadow-host) (changedTouches: shadow-host) mousewheel @shadow-host (target: shadow-host) @top (target: shadow-host) PASS successfullyParsed is true TEST COMPLETE