RenderListItem should store its marker in a RenderPtr.
Created attachment 220117 [details] Patch
Comment on attachment 220117 [details] Patch Attachment 220117 [details] did not pass mac-wk2-ews (mac-wk2): Output: http://webkit-queues.appspot.com/results/6297786244923392
Committed r161183: <http://trac.webkit.org/changeset/161183>