Implemented stub for NavigatorPlugins

components/script/dom/webidls/PluginArray.webidl

@@ -0,0 +1,13 @@
+/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 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/. */
+
+// https://html.spec.whatwg.org/multipage/#pluginarray
+[LegacyUnenumerableNamedProperties]
+interface PluginArray {
+  void refresh(optional boolean reload = false);
+  readonly attribute unsigned long length;
+  getter Plugin? item(unsigned long index);
+  getter Plugin? namedItem(DOMString name);
+};