RenderBox::willBeDestroyed() does a couple of things, but none of them require the renderer to be in-tree, nor does it do any virtual dispatch.
We should move the logic to the plain destructor and get rid of the hook.
Created attachment 240942 [details]
Comment on attachment 240942 [details]
Clearing flags on attachment: 240942
Committed r175580: <http://trac.webkit.org/changeset/175580>
All reviewed patches have been landed. Closing bug.