google/web-starter-kit — pull request #239 by addyosmani (2014-07-03 10:49:14+00:00)
Title: Potential fix for #79

In the 1200px media query, negate the `.app-bar.open, .app-bar.open ~
main transform` to remove the white area (~250px out) displayed. This
generally seems to be a FF only issue.