Add analytics to changelog pages to track usage

perf/dashboard/ui/changelog.html

Index: perf/dashboard/ui/changelog.html
===================================================================
--- perf/dashboard/ui/changelog.html	(revision 298504)
+++ perf/dashboard/ui/changelog.html	(working copy)
@@ -66,6 +66,14 @@
 var svnRange = params["range"];
 render_log(svnRootUrl, svnPath, svnRange, viewVc)
 </script>
+<script>
+  (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-55762617-21', 'auto');
+    ga('send', 'pageview');
+</script>
 </body>
 </html>