First try at a user management screen for the desktop

chrome/browser/resources/user_chooser/user_chooser.js

+// Copyright (c) 2012 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';
+
+  /**
+   * Setups given "select" element using the list and adds callback.
+   * @param {!Element} select Select object to be updated.
+   * @param {!Object} list List of the options to be added.
+   * @param {string} callback Callback name which should be send to Chrome or
+   * an empty string if the event listener shouldn't be added.
+   */
+  function setupSelect(select, list, callback) {
+    select.options.length = 0;
+    for (var i = 0; i < list.length; ++i) {
+      var item = list[i];
+      var option =
+          new Option(item.title, item.value, item.selected, item.selected);
+      select.appendChild(option);
+    }
+    if (callback) {
+      var sendCallback = function() {
+        chrome.send(callback, [select.options[select.selectedIndex].value]);
+      };
+      select.addEventListener('blur', sendCallback);
+      select.addEventListener('click', sendCallback);
+      select.addEventListener('keyup', function(event) {
+        var keycodeInterested = [
+          9,  // Tab
+          13,  // Enter
+          27,  // Escape
+        ];
+        if (keycodeInterested.indexOf(event.keyCode) >= 0)
+          sendCallback();
+      });
+    }
+  }
+
+  function initialize() {
+    login.AccountPickerScreen.register();
+    login.GaiaSigninScreen.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,
+    setupSelect: setupSelect
+  };
+});
+
+document.addEventListener('DOMContentLoaded', UserChooser.initialize);