discourse/app/views/common/_google_analytics.html.erb

<script type="text/javascript">

  var _gaq = _gaq || [];
  _gaq.push(['_setAccount', '<%= SiteSetting.ga_tracking_code %>']);

  <% if SiteSetting.ga_domain_name.present? %>
    _gaq.push(['_setDomainName', '<%= SiteSetting.ga_domain_name.gsub(/^http(s)?:\/\//, '') %>']);
  <% end %>

  _gaq.push(['_setCustomVar', 1, 'Anonymous', <%= !current_user %>, 2]);
  _gaq.push(['_trackPageview']);

  (function() {
    var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
    ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
    var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
  })();

</script>