Add Google Analytics if settings supply it

src/sidebar/app.js

 'use strict';
 
 var queryString = require('query-string');
+var addAnalytics = require('./ga');
 
 require('../shared/polyfills');
 
@@ -37,6 +38,10 @@ if (settings.raven) {
   angular.module('ngRaven', []);
 }
 
+if(settings.googleAnalytics){
+  addAnalytics(settings.googleAnalytics);
+}
+
 // Fetch external state that the app needs before it can run. This includes the
 // authenticated user state, the API endpoint URLs and WebSocket connection.
 var resolve = {

src/sidebar/ga.js

+'use strict';
+
+let loaded = false;
+
+module.exports = function(trackingId){
+
+  // small measure to make we do not accidentally
+  // load the analytics scripts more than once
+  if(loaded){
+    return;
+  }
+
+  loaded = true;
+
+  /* eslint-disable */
+
+  // Google Analytics snippet to load the analytics 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','https://www.google-analytics.com/analytics.js','ga');
+
+  ga('create', trackingId, 'auto');
+
+  // overrides helper that requires http or https protocols.
+  // obvious issue when it comes to extensions with protocols
+  // like "chrome-extension://" but isn't a huge need for us
+  // anywhere else as well.
+  // https://developers.google.com/analytics/devguides/collection/analyticsjs/tasks#disabling
+  ga('set', 'checkProtocolTask', null);
+
+  /* eslint-enable */
+};