Fixing touch scrolling support for devices that support it natively. Our current touch support overrides native touch scrolling on tablets, which breaks touch scrolling.

Review at http://gwt-code-reviews.appspot.com/1369809

Review by: pdr@google.com

git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@9852 8db76d5a-ed1c-0410-87a9-c151d255dfc7