The :matches()selector was renamed to :is() in https://github.com/w3c/csswg-drafts/issues/3258 :matches() is no longer supported by some browsers (like Chromium and Firefox) and breaks Web Inspector UI in such browsers when we connect via HTTP. In case GTK/WPE WebKit, we use HTTP version of the inspector and it can be used from any browser. In Firefox we get warning: "Unknown pseudo-class or pseudo-element ‘matches’. Ruleset ignored due to bad selector"
Pull request: https://github.com/WebKit/WebKit/pull/10927
Committed 261264@main (1e4c1a8d21b7): <https://commits.webkit.org/261264@main> Reviewed commits have been landed. Closing PR #10927 and removing active labels.
<rdar://problem/106280337>