These classes should not be in WebCore, but in WebKit, since they are only expected to be used there.
Created attachment 403894 [details] Patch
Created attachment 403899 [details] Patch
Created attachment 403902 [details] Patch
Created attachment 403911 [details] Patch
Created attachment 403917 [details] Patch
Thanks for reviewing!
Committed r264199: <https://trac.webkit.org/changeset/264199> All reviewed patches have been landed. Closing bug and clearing flags on attachment 403917 [details].
<rdar://problem/65292581>