<rdar://90952989> I don't think there's a need to synchronously flush from destruction, we should be able to just flush without waiting. This hopefully improves PLT performance when navigating between pages (haven't managed to get a successful AB test on the bots).
Created attachment 459463 [details] Patch
Created attachment 459514 [details] Patch for landing
Created attachment 459515 [details] Patch for landing
Committed r294355 (250662@main): <https://commits.webkit.org/250662@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 459515 [details].