Adding Element#getPreviousSibling().

Issue: 3670

Review at http://gwt-code-reviews.appspot.com/1581803

Review by: skybrian@google.com

git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@10722 8db76d5a-ed1c-0410-87a9-c151d255dfc7
3 files changed