Implement :has-slotted pseudo class
This pseudo class matches the presence of assigned nodes in the slot
element.
https://drafts.csswg.org/css-scoping-1/#the-has-slotted-pseudo
Bug: 369883705
Change-Id: I7c848204d7c39860f39fab19290ef366e94d0a3e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5899636
Reviewed-by: Joey Arhar jarhar@chromium.org
Reviewed-by: Luke lwarlow@igalia.com
Auto-Submit: Keith Cirkel chromium@keithcirkel.co.uk
Commit-Queue: Keith Cirkel chromium@keithcirkel.co.uk
Cr-Commit-Position: refs/heads/main@{#1363222}