show error page on firefox v49 and below

frontend/src/common.js

@@ -3,8 +3,24 @@ window.Raven.config(window.dsn).install();
 window.dsn = undefined;
 
 const testPilotGA = require('testpilot-ga');
+const {gcmCompliant, sendEvent} = require('./utils');
 window.analytics = new testPilotGA({
   an: 'Firefox Send',
   ds: 'web',
   tid: window.trackerId
 });
+
+gcmCompliant().catch(err => {
+  $('#page-one').attr('hidden', true);
+  $('#download').attr('hidden', true);
+  sendEvent('sender', 'unsupported', {
+    cd6: err
+  }).then(() => {
+    location.replace('/unsupported');
+  });
+});
+
+if (navigator.userAgent.toLowerCase().indexOf('firefox') > -1 &&
+    parseInt(navigator.userAgent.toLowerCase().match(/firefox\/*([^\n\r]*)\./)[1]) <= 49) {
+    location.replace('/unsupported');
+}

frontend/src/download.js

@@ -1,6 +1,6 @@
 require('./common');
 const FileReceiver = require('./fileReceiver');
-const { notify, findMetric, gcmCompliant, sendEvent } = require('./utils');
+const { notify, findMetric, sendEvent } = require('./utils');
 const bytes = require('bytes');
 const Storage = require('./storage');
 const storage = new Storage(localStorage);
@@ -11,14 +11,6 @@ require('jquery-circle-progress');
 const Raven = window.Raven;
 
 $(document).ready(function() {
-  gcmCompliant().catch(err => {
-    $('#download').attr('hidden', true);
-    sendEvent('recipient', 'unsupported', {
-      cd6: err
-    }).then(() => {
-      location.replace('/unsupported');
-    });
-  });
   //link back to homepage
   $('.send-new').attr('href', window.location.origin);
 

frontend/src/upload.js

@@ -3,7 +3,6 @@ require('./common');
 const FileSender = require('./fileSender');
 const {
   notify,
-  gcmCompliant,
   findMetric,
   sendEvent,
   ONE_DAY_IN_MS
@@ -25,15 +24,6 @@ if (storage.has('referrer')) {
 }
 
 $(document).ready(function() {
-  gcmCompliant().catch(err => {
-    $('#page-one').attr('hidden', true);
-    sendEvent('sender', 'unsupported', {
-      cd6: err
-    }).then(() => {
-      location.replace('/unsupported');
-    });
-  });
-
   $('#file-upload').change(onUpload);
 
   $('.legal-links a, .social-links a, #dl-firefox').click(function(target) {