Use RenderObject::firstChildSlow() / lastChildSlow() less by using tighter typing at call sites whenever possible to be able to call RenderElement::firstChild() / lastChild() instead.
Created attachment 239567 [details] Patch
Created attachment 239570 [details] Patch
Comment on attachment 239570 [details] Patch r=me
Comment on attachment 239570 [details] Patch Clearing flags on attachment: 239570 Committed r174542: <http://trac.webkit.org/changeset/174542>
All reviewed patches have been landed. Closing bug.