Make the UserContentController for ServiceWorker pages be non-optional <rdar://problem/71434565>
Created attachment 419464 [details] EWS
Created attachment 419470 [details] EWS2
Created attachment 419483 [details] EWS3
Created attachment 419487 [details] EWS4
Created attachment 419622 [details] Patch
Committed r272550: <https://commits.webkit.org/r272550> All reviewed patches have been landed. Closing bug and clearing flags on attachment 419622 [details].