Remove runtime setting for enabling/disabling custom elements. They should always be enabled now.
Created attachment 408783 [details] Patch
Created attachment 408821 [details] Patch
Created attachment 408836 [details] Patch
commit-queue failed to commit attachment 408836 [details] to WebKit repository.
Committed r267095: <https://trac.webkit.org/changeset/267095>
<rdar://problem/68936131>