diff -r 000000000000 -r 6474c204b198 toolkit/components/startup/tests/unit/head_startup.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/components/startup/tests/unit/head_startup.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,57 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+const XULRUNTIME_CONTRACTID = "@mozilla.org/xre/runtime;1";
+const XULRUNTIME_CID = Components.ID("7685dac8-3637-4660-a544-928c5ec0e714}");
+
+Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
+
+let gAppInfo = null;
+
+function createAppInfo(id, name, version, platformVersion) {
+  gAppInfo = {
+    // nsIXULAppInfo
+    vendor: "Mozilla",
+    name: name,
+    ID: id,
+    version: version,
+    appBuildID: "2007010101",
+    platformVersion: platformVersion ? platformVersion : "1.0",
+    platformBuildID: "2007010101",
+
+    // nsIXULRuntime
+    inSafeMode: false,
+    logConsoleErrors: true,
+    OS: "XPCShell",
+    replacedLockTime: 0,
+    XPCOMABI: "noarch-spidermonkey",
+    invalidateCachesOnRestart: function invalidateCachesOnRestart() {
+      // Do nothing
+    },
+
+    // nsICrashReporter
+    annotations: {
+    },
+
+    annotateCrashReport: function(key, data) {
+      this.annotations[key] = data;
+    },
+
+    QueryInterface: XPCOMUtils.generateQI([Ci.nsIXULAppInfo,
+                                           Ci.nsIXULRuntime,
+                                           Ci.nsICrashReporter,
+                                           Ci.nsISupports])
+  };
+
+  let XULAppInfoFactory = {
+    createInstance: function (outer, iid) {
+      if (outer != null)
+        throw Components.results.NS_ERROR_NO_AGGREGATION;
+      return gAppInfo.QueryInterface(iid);
+    }
+  };
+  let registrar = Components.manager.QueryInterface(Ci.nsIComponentRegistrar);
+  registrar.registerFactory(XULRUNTIME_CID, "XULRuntime",
+                            XULRUNTIME_CONTRACTID, XULAppInfoFactory);
+
+}