diff -r 000000000000 -r 6474c204b198 toolkit/components/captivedetect/test/unit/head_setprefs.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/components/captivedetect/test/unit/head_setprefs.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,49 @@
+/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+'use strict';
+
+const {classes: Cc, interfaces: Ci, utils: Cu, results: Cr} = Components;
+
+Cu.import('resource://gre/modules/XPCOMUtils.jsm');
+Cu.import('resource://gre/modules/Services.jsm');
+Cu.import('resource://testing-common/httpd.js');
+
+XPCOMUtils.defineLazyServiceGetter(this, 'gCaptivePortalDetector',
+                                   '@mozilla.org/toolkit/captive-detector;1',
+                                   'nsICaptivePortalDetector');
+
+const kCanonicalSitePath = '/canonicalSite.html';
+const kCanonicalSiteContent = 'true';
+const kPrefsCanonicalURL = 'captivedetect.canonicalURL';
+const kPrefsCanonicalContent = 'captivedetect.canonicalContent';
+const kPrefsMaxWaitingTime = 'captivedetect.maxWaitingTime';
+const kPrefsPollingTime = 'captivedetect.pollingTime';
+
+var gServer;
+var gServerURL;
+
+function setupPrefs() {
+  let prefs = Components.classes["@mozilla.org/preferences-service;1"]
+                .getService(Components.interfaces.nsIPrefService)
+                .QueryInterface(Components.interfaces.nsIPrefBranch);
+  prefs.setCharPref(kPrefsCanonicalURL, gServerURL + kCanonicalSitePath);
+  prefs.setCharPref(kPrefsCanonicalContent, kCanonicalSiteContent);
+  prefs.setIntPref(kPrefsMaxWaitingTime, 0);
+  prefs.setIntPref(kPrefsPollingTime, 1);
+}
+
+function run_captivedetect_test(xhr_handler, fakeUIResponse, testfun)
+{
+  gServer = new HttpServer();
+  gServer.registerPathHandler(kCanonicalSitePath, xhr_handler);
+  gServer.start(-1);
+  gServerURL = 'http://localhost:' + gServer.identity.primaryPort;
+
+  setupPrefs();
+
+  fakeUIResponse();
+
+  testfun();
+}