import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

browser/base/content/browser-tabsintitlebar-stub.js

@@ -0,0 +1,17 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 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/. */
+
+// This file is used as a stub object for platforms which
+// don't have CAN_DRAW_IN_TITLEBAR defined.
+
+var TabsInTitlebar = {
+  init: function () {},
+  uninit: function () {},
+  allowedBy: function (condition, allow) {},
+  updateAppearance: function updateAppearance(aForce) {},
+  get enabled() {
+    return document.documentElement.getAttribute("tabsintitlebar") == "true";
+  },
+};