Descriptors for @counter-style rules were added in https://bugs.webkit.org/show_bug.cgi?id=224718 but not marked as "descriptor-only".
Created attachment 430912 [details] Patch
Created attachment 430920 [details] Patch
Committed r278667 (238649@main): <https://commits.webkit.org/238649@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 430920 [details].
<rdar://problem/79088911>