Add managed preference for iOS to allow enterprise customers to keep using legacy sync XHRs during page dismissal.
<rdar://problem/58440111>
Created attachment 389153 [details] Patch
Comment on attachment 389153 [details] Patch Clearing flags on attachment: 389153 Committed r255366: <https://trac.webkit.org/changeset/255366>
All reviewed patches have been landed. Closing bug.
Follow-up Catalyst build fix in <https://trac.webkit.org/changeset/255376>.