check whether we are running on mario before executing mario specific workarounds. Change-Id: I79b948ab296da421271ab8edf61c49608272326e BUG=chromium-os:12822 TEST=TBD Review URL: http://codereview.chromium.org/6691012 (cherry picked from commit 4ffa550605d6d5a26d075f9341c120250200dd97) Review URL: http://codereview.chromium.org/6683051