expanding priority list is as follows: fixed percent relative auto
Created attachment 432795 [details] Patch
Created attachment 432840 [details] Patch
Created attachment 432850 [details] Patch
Committed r279543 (239379@main): <https://commits.webkit.org/239379@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 432850 [details].
<rdar://problem/80127101>