There used to be more classes inheriting from SVGLocatable, so virtual inheritance was used to avoid base duplication. This is no longer an issue since SVGTransformable is the only thing that inherits SVGLocatable.
Created attachment 274830 [details] Patch
Comment on attachment 274830 [details] Patch Clearing flags on attachment: 274830 Committed r198626: <http://trac.webkit.org/changeset/198626>
All reviewed patches have been landed. Closing bug.