First try at a user management screen for the desktop

chrome/browser/resources/user_chooser/user_chooser.js

+// Copyright (c) 2013 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.
+<include src="user_chooser_common.js"></include>
+
+cr.define('UserChooser', function() {
+  'use strict';
+
+  function initialize() {
+    login.AccountPickerScreen.register();
+    cr.ui.Bubble.decorate($('bubble'));
+    login.HeaderBar.decorate($('login-header-bar'));
+    chrome.send('userChooserInitialize');
+  }
+
+  // Return an object with all of the exports.
+  return {
+    initialize: initialize
+  };
+});
+
+document.addEventListener('DOMContentLoaded', UserChooser.initialize);