MD Settings: make <paper-drawer-panel> flip in RTL

chrome/browser/resources/settings/direction_delegate.js

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+cr.exportPath('settings');
+
+/** @interface */
+settings.DirectionDelegate = function() {};
+
+settings.DirectionDelegate.prototype = {
+  /**
+   * @return {boolean} Whether the direction of the settings UI is
+   *     right-to-left.
+   */
+  isRtl: assertNotReached,
+};
+
+/**
+ * @implements {settings.DirectionDelegate}
+ * @constructor
+ */
+settings.DirectionDelegateImpl = function() {};
+
+settings.DirectionDelegateImpl.prototype = {
+  /** @override */
+  isRtl: function() {
+    return loadTimeData.getString('textdirection') == 'rtl';
+  },
+};