According to the Core AAM:
1. When the aria-activedescendant of an element changes, we should emit object:state-changed:focused. We don't.
2. When a focused element has a valid active descendant, we should not exposed the focused state on the element, but rather on the active descendant. We expose it on the element.
3. The active descendant should have the focusable state even though the element itself might not technically be keyboard focusable. (The author is expected to make it work.) We don't.
Created attachment 324249 [details]
Comment on attachment 324249 [details]
Clearing flags on attachment: 324249
Committed r223766: <https://trac.webkit.org/changeset/223766>
All reviewed patches have been landed. Closing bug.