The apis exposed to ShadowRealm via the [Exposed=*] extended attribute are not yet fully agreed upon. It may be worth hiding them behind a feature flag in the mean time, while still shipping what major stakeholders are interested in.
Patch is on https://github.com/WebKit/WebKit/pull/1382
Committed r295459 (251465@main): <https://commits.webkit.org/251465@main> Reviewed commits have been landed. Closing PR #1382 and removing active labels.
<rdar://problem/94830589>