ぼくのかんがえたさいきょうのGoogle Analyticsマルチトラッキング用読み込みコード ref: http://qiita.com/takustaqu/items/0690c2a9da3331a728e3

file0.html

<script>
    var sites = [['UA-XXXXXXXX-X'],['UA-XXXXXXXX-X','trackB'],['UA-XXXXXXXX-X','trackC']];
    window.ga=window.ga||function(){(ga.q=ga.q||[]).push(arguments)};ga.l=+new Date;
    !function(a){var n=[];a.forEach(function(a){var t=a[1],o=t?{name:t}:{};ga("create",a[0],"auto",o),n.push((t?t+".":"")+"send")}),window.gall=function(){var a,t,o=n,r=arguments;o.forEach(function(n){var o=[n];for(a=0,t=r.length;t>a;a++)o.push(r[a]);ga.apply(this,o)})}}(sites);

    gall('pageview');
</script>
<script async src='//www.google-analytics.com/analytics.js'></script>

file0.txt

<script>
    var sites = [['UA-XXXXXXXX-X'],['UA-XXXXXXXX-X','trackB'],['UA-XXXXXXXX-X','trackC']];
    window.ga=window.ga||function(){(ga.q=ga.q||[]).push(arguments)};ga.l=+new Date;
    !function(a){var n=[];a.forEach(function(a){var t=a[1],o=t?{name:t}:{};ga("create",a[0],"auto",o),n.push((t?t+".":"")+"send")}),window.gall=function(){var a,t,o=n,r=arguments;o.forEach(function(n){var o=[n];for(a=0,t=r.length;t>a;a++)o.push(r[a]);ga.apply(this,o)})}}(sites);

    gall('pageview');
</script>
<script async src='//www.google-analytics.com/analytics.js'></script>