diff -r 000000000000 -r 6474c204b198 browser/components/customizableui/test/browser_940946_removable_from_navbar_customizemode.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/components/customizableui/test/browser_940946_removable_from_navbar_customizemode.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,22 @@
+/* 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 kTestBtnId = "test-removable-navbar-customize-mode";
+
+// Items without the removable attribute in the navbar should be considered non-removable
+add_task(function() {
+  let btn = createDummyXULButton(kTestBtnId, "Test removable in navbar in customize mode");
+  document.getElementById("nav-bar").customizationTarget.appendChild(btn);
+  yield startCustomizing();
+  ok(!CustomizableUI.isWidgetRemovable(kTestBtnId), "Widget should not be considered removable");
+  yield endCustomizing();
+  document.getElementById(kTestBtnId).remove();
+});
+
+add_task(function asyncCleanup() {
+  yield endCustomizing();
+  yield resetCustomization();
+});