Changes all aura code to use windows scrollbars

Apparently we're going to go with the windows style on chromeos and
desktop linux too.

BUG=333499 338462
TEST=none
R=sadrul@chromium.org

Review URL: https://codereview.chromium.org/152123005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@250105 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 250105