This abstraction is not really useful as is.
Created attachment 319314 [details] Patch
Created attachment 319368 [details] Patch
Comment on attachment 319368 [details] Patch Clearing flags on attachment: 319368 Committed r221397: <http://trac.webkit.org/changeset/221397>
All reviewed patches have been landed. Closing bug.
<rdar://problem/34172067>