diff -r 000000000000 -r 6474c204b198 toolkit/components/passwordmgr/test/prompt_common.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/components/passwordmgr/test/prompt_common.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,72 @@
+var Ci = SpecialPowers.Ci;
+ok(Ci != null, "Access Ci");
+var Cc = SpecialPowers.Cc;
+ok(Cc != null, "Access Cc");
+
+var didDialog;
+
+var timer; // keep in outer scope so it's not GC'd before firing
+function startCallbackTimer() {
+    didDialog = false;
+
+    // Delay before the callback twiddles the prompt.
+    const dialogDelay = 10;
+
+    // Use a timer to invoke a callback to twiddle the authentication dialog
+    timer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
+    timer.init(observer, dialogDelay, Ci.nsITimer.TYPE_ONE_SHOT);
+}
+
+
+var observer = SpecialPowers.wrapCallbackObject({
+    QueryInterface : function (iid) {
+        const interfaces = [Ci.nsIObserver,
+                            Ci.nsISupports, Ci.nsISupportsWeakReference];
+
+        if (!interfaces.some( function(v) { return iid.equals(v) } ))
+            throw SpecialPowers.Components.results.NS_ERROR_NO_INTERFACE;
+        return this;
+    },
+
+    observe : function (subject, topic, data) {
+        var doc = getDialogDoc();
+        if (doc)
+            handleDialog(doc, testNum);
+        else
+            startCallbackTimer(); // try again in a bit
+    }
+});
+
+function getDialogDoc() {
+  // Find the <browser> which contains notifyWindow, by looking
+  // through all the open windows and all the <browsers> in each.
+  var wm = Cc["@mozilla.org/appshell/window-mediator;1"].
+           getService(Ci.nsIWindowMediator);
+  //var enumerator = wm.getEnumerator("navigator:browser");
+  var enumerator = wm.getXULWindowEnumerator(null);
+
+  while (enumerator.hasMoreElements()) {
+    var win = enumerator.getNext();
+    var windowDocShell = win.QueryInterface(Ci.nsIXULWindow).docShell;
+
+    var containedDocShells = windowDocShell.getDocShellEnumerator(
+                                      Ci.nsIDocShellTreeItem.typeChrome,
+                                      Ci.nsIDocShell.ENUMERATE_FORWARDS);
+    while (containedDocShells.hasMoreElements()) {
+        // Get the corresponding document for this docshell
+        var childDocShell = containedDocShells.getNext();
+        // We don't want it if it's not done loading.
+        if (childDocShell.busyFlags != Ci.nsIDocShell.BUSY_FLAGS_NONE)
+          continue;
+        var childDoc = childDocShell.QueryInterface(Ci.nsIDocShell)
+                                    .contentViewer
+                                    .DOMDocument;
+
+        //ok(true, "Got window: " + childDoc.location.href);
+        if (childDoc.location.href == "chrome://global/content/commonDialog.xul")
+          return childDoc;
+    }
+  }
+
+  return null;
+}