Tests: https://github.com/web-platform-tests/wpt/pull/58397 Specification changes: https://github.com/whatwg/html/pull/12239 & https://github.com/whatwg/webidl/pull/1421
Tests: web-platform-tests/wpt#58397
Specification changes: whatwg/html#12239 & whatwg/webidl#1421