In Element::attach(), Node::attach() is called before attaching children if a shadow root exists. This may cause O(N^2) problem in NodeRenderingContext.
Created attachment 128138 [details] Patch
Comment on attachment 128138 [details] Patch Clearing flags on attachment: 128138 Committed r108470: <http://trac.webkit.org/changeset/108470>
All reviewed patches have been landed. Closing bug.