Send Viewport data to Google Analytics (Universal), based on example at http://viget.com/advance/upgrading-to-universal-analytics

analytics.js

(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
(i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
})(window,document,'script','//www.google-analytics.com/analytics.js','ga');

ga('create', 'UA-YOURIDHERE', 'auto');
ga('send', 'pageview');

var w = window,
d = document,
e = d.documentElement,
g = d.getElementsByTagName('body')[0],
width = w.innerWidth||e.clientWidth||g.clientWidth,
height = w.innerHeight||e.clientHeight||g.clientHeight;
ga('send', 'event', 'Viewport', 'Size', width + 'x' + height, 0, {'nonInteraction': 1});
ga('send', 'event', 'Viewport', 'Width', width + 'x' + height, width, {'nonInteraction': 1});
ga('send', 'event', 'Viewport', 'Height', width + 'x' + height, height, {'nonInteraction': 1});
ga('send', 'event', 'Viewport', 'Aspect Ratio X 100', width + 'x' + height, Math.round((width / height) * 100), {'nonInteraction': 1});