Rather than expect all subclasses to override `parentObject`, we can provide a stub implementation that does nothing so that we never have to worry about calling a pure virtual function (if we missed a subclass).
Created attachment 367655 [details]
Created attachment 367656 [details]
Comment on attachment 367656 [details]
Clearing flags on attachment: 367656
Committed r244394: <https://trac.webkit.org/changeset/244394>
All reviewed patches have been landed. Closing bug.