[CTTE] Tighten RenderTextControl element typing.
Created attachment 211508 [details] Patch
Comment on attachment 211508 [details] Patch Attachment 211508 [details] did not pass qt-ews (qt): Output: http://webkit-queues.appspot.com/results/1852045
Comment on attachment 211508 [details] Patch Attachment 211508 [details] did not pass qt-wk2-ews (qt-wk2): Output: http://webkit-queues.appspot.com/results/1841121
Committed r155671: <http://trac.webkit.org/changeset/155671>