Chrome 34 detects the correct breakpoint

Fixes [a bug](http://codepen.io/kaelig/pen/BDaqc) where Chrome 34 would not compute the styles of a hidden pseudo element, making the detect.js script bug. Meaning lots of layout decisions would be wrong in Chrome 34.

@michaelmcnamara can you cross browser test this to make sure there was no regression involved in the process?

![ ](http://1.bp.blogspot.com/-wLDHAATaruE/UuzcMSmyNlI/AAAAAAABFoQ/JpcSL6GyAwk/s1600/dog-loves-watching-tennis.gif)