[cros] Pre-select the first user pod on login screen.

chrome/browser/resources/chromeos/login/screen_account_picker.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.
 
 /**
  * @fileoverview Account picker screen implementation.
  */
 
 cr.define('login', function() {
   /**
    * Maximum number of offline login failures before online login.
-     @type {number}
-     @const
+   * @type {number}
+   * @const
    */
   var MAX_LOGIN_ATTEMPTS_IN_POD = 3;
 
   /**
+   * Whether to preselect the first pod automatically on login screen.
+   * @type {boolean}
+   * @const
+   */
+  var PRESELECT_FIRST_POD = true;
+
+  /**
    * Creates a new account picker screen div.
    * @constructor
    * @extends {HTMLDivElement}
    */
   var AccountPickerScreen = cr.ui.define('div');
 
   /**
    * Registers with Oobe.
    */
   AccountPickerScreen.register = function() {
@@ skipping 34 matching lines @@
     onBeforeShow: function(data) {
       chrome.send('hideCaptivePortal');
       var podRow = $('pod-row');
       podRow.handleShow();
 
       // If this is showing for the lock screen display the sign out button,
       // hide the add user button and activate the locked user's pod.
       var lockedPod = podRow.lockedPod;
       $('add-user-header-bar-item').hidden = !!lockedPod;
       $('sign-out-user-item').hidden = !lockedPod;
-      if (lockedPod) {
+      var preselectedPod = PRESELECT_FIRST_POD ?
+          lockedPod || podRow.pods[0] : lockedPod;
+      if (preselectedPod) {
         // TODO(altimofeev): empirically I investigated that focus isn't
         // set correctly if following CSS rules are present:
         //
         // podrow {
         //   -webkit-transition: all 200ms ease-in-out;
         // }
         // .pod {
         //  -webkit-transition: all 230ms ease;
         // }
         //
         // Workaround is either delete these rules or delay the focus setting.
         var self = this;
-        lockedPod.addEventListener('webkitTransitionEnd', function f(e) {
-          if (e.target == lockedPod) {
-            podRow.focusPod(lockedPod);
-            lockedPod.removeEventListener(f);
+        preselectedPod.addEventListener('webkitTransitionEnd', function f(e) {
+          if (e.target == preselectedPod) {
+            podRow.focusPod(preselectedPod);
+            preselectedPod.removeEventListener(f);
             // Delay the accountPickerReady signal so that if there are any
             // timeouts waiting to fire we can process these first. This was
             // causing crbug.com/112218 as the account pod was sometimes focuse
             // using focusPod (which resets the password) after the test code
             // set the password.
             self.onShow();
           }
         });
       } else {
         this.onShow();
@@ skipping 74 matching lines @@
    * @param {boolean} enabled Whether Caps Lock is on.
    */
   AccountPickerScreen.setCapsLockState = function(enabled) {
     $('pod-row').classList[enabled ? 'add' : 'remove']('capslock-on');
   };
 
   return {
     AccountPickerScreen: AccountPickerScreen
   };
 });