Make sure that if NetworkProcess clears DOMCache, it also clears service worker registrations
<rdar://problem/72360003>
Created attachment 417174 [details] Patch
Created attachment 417258 [details] Reuploading to run on bots
Found 1 new test failure: media/controls/showControlsButton.html
Committed r271291: <https://trac.webkit.org/changeset/271291> All reviewed patches have been landed. Closing bug and clearing flags on attachment 417258 [details].