diff -r 000000000000 -r 6474c204b198 services/crypto/tests/unit/head_helpers.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/services/crypto/tests/unit/head_helpers.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,73 @@
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+const Cr = Components.results;
+const Cu = Components.utils;
+
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+
+try {
+  // In the context of xpcshell tests, there won't be a default AppInfo
+  Cc["@mozilla.org/xre/app-info;1"].getService(Ci.nsIXULAppInfo);
+}
+catch(ex) {
+
+// Make sure to provide the right OS so crypto loads the right binaries
+let OS = "XPCShell";
+if ("@mozilla.org/windows-registry-key;1" in Cc)
+  OS = "WINNT";
+else if ("nsILocalFileMac" in Ci)
+  OS = "Darwin";
+else
+  OS = "Linux";
+
+let XULAppInfo = {
+  vendor: "Mozilla",
+  name: "XPCShell",
+  ID: "{3e3ba16c-1675-4e88-b9c8-afef81b3d2ef}",
+  version: "1",
+  appBuildID: "20100621",
+  platformVersion: "",
+  platformBuildID: "20100621",
+  inSafeMode: false,
+  logConsoleErrors: true,
+  OS: OS,
+  XPCOMABI: "noarch-spidermonkey",
+  QueryInterface: XPCOMUtils.generateQI([Ci.nsIXULAppInfo, Ci.nsIXULRuntime])
+};
+
+let XULAppInfoFactory = {
+  createInstance: function (outer, iid) {
+    if (outer != null)
+      throw Cr.NS_ERROR_NO_AGGREGATION;
+    return XULAppInfo.QueryInterface(iid);
+  }
+};
+
+let registrar = Components.manager.QueryInterface(Ci.nsIComponentRegistrar);
+registrar.registerFactory(Components.ID("{fbfae60b-64a4-44ef-a911-08ceb70b9f31}"),
+                          "XULAppInfo", "@mozilla.org/xre/app-info;1",
+                          XULAppInfoFactory);
+
+}
+
+// Register resource alias. Normally done in SyncComponents.manifest.
+function addResourceAlias() {
+  Cu.import("resource://gre/modules/Services.jsm");
+  const resProt = Services.io.getProtocolHandler("resource")
+                          .QueryInterface(Ci.nsIResProtocolHandler);
+  let uri = Services.io.newURI("resource://gre/modules/services-crypto/",
+                               null, null);
+  resProt.setSubstitution("services-crypto", uri);
+}
+addResourceAlias();
+
+/**
+ * Print some debug message to the console. All arguments will be printed,
+ * separated by spaces.
+ *
+ * @param [arg0, arg1, arg2, ...]
+ *        Any number of arguments to print out
+ * @usage _("Hello World") -> prints "Hello World"
+ * @usage _(1, 2, 3) -> prints "1 2 3"
+ */
+let _ = function(some, debug, text, to) print(Array.slice(arguments).join(" "));