This is a split from the original bug 240223 patch. This will help the migration to the future SharedMemory transfer between processes.
<rdar://problem/93806688>
Pull request: https://github.com/WebKit/WebKit/pull/971
Committed r294784 (250943@main): <https://commits.webkit.org/250943@main> Reviewed commits have been landed. Closing PR #971 and removing active labels.