Update from latest upstream webkit

commit 6bca3489653eaed3f3bc0bbdc8887abd2879887e
Author: zandobersek@gmail.com <zandobersek@gmail.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc>
Date:   Tue Oct 1 12:09:15 2013 +0000

    Fix the 'InexedDB' typo in the ChangeLog that I failed to address prior to landing r156701.

    git-svn-id: http://svn.webkit.org/repository/webkit/trunk@156708 268f45cc-cd09-0410-ab3c-d52691b4dbfc