Revert "MD user manager (learn more page, user manager tutorial)"

chrome/browser/resources/md_user_manager/control_bar.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.
 
 /**
  * @fileoverview 'control-bar' is the horizontal bar at the bottom of the user
  * manager screen.
+ *
+ * @element control-bar
  */
  Polymer({
   is: 'control-bar',
 
   properties: {
     /**
      * True if 'Browse as Guest' button is displayed.
      * @type {boolean}
      */
     showGuest: {
@@ skipping 31 matching lines @@
   /**
    * Handler for 'Add Person' button click event.
    * @param {!Event} event
    * @private
    */
   onAddUserTap_: function(event) {
     // Event is caught by user-manager-pages.
     this.fire('change-page', {page: 'create-user-page'});
   }
 });