Fix cross-frame horizontal scrolling on the uber page.

Documents in standards mode should now refer to document.documentElement.scroll{Left,Top}. 

document.body.scroll{Left,Top} is deprecated.

R=arv@chromium.org
BUG=305745

Review URL: https://codereview.chromium.org/26719003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@227836 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 227836