This is a basic implementaion to support execCommand("undo") in Javascript. I refered to GTK+ port.
Created attachment 96226 [details] Proposed patch
LGTM.
Comment on attachment 96226 [details] Proposed patch LGTM
Comment on attachment 96226 [details] Proposed patch Clearing flags on attachment: 96226 Committed r88354: <http://trac.webkit.org/changeset/88354>
All reviewed patches have been landed. Closing bug.