Copying a MIME type map from the UI process to the WebContent process on startup is not needed anymore, since r258891 will map the Launch Services database in the WebContent process.
Created attachment 397694 [details]
Created attachment 397699 [details]
Committed r260769: <https://trac.webkit.org/changeset/260769>
All reviewed patches have been landed. Closing bug and clearing flags on attachment 397699 [details].
Re-opened since this is blocked by bug 211578