cros: Fixed 3 bugs for pin unlock.

ui/login/account_picker/screen_account_picker.js

 // Copyright 2014 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.
  */
 
 login.createScreen('AccountPickerScreen', 'account-picker', function() {
   /**
@@ skipping 206 matching lines @@
                                               error,
                                               BUBBLE_OFFSET, BUBBLE_PADDING);
           };
           activatedPod.addEventListener("webkitTransitionEnd", showTopCallback);
           ensureTransitionEndEvent(activatedPod);
         }
       }
     },
 
     /**
-     * Loads the PIN keyboard if any of the users can login with a PIN.
+     * Loads the PIN keyboard if any of the users can login with a PIN. Disables
+     * the PIN keyboard for users who are not allowed to use PIN unlock.
      * @param {array} users Array of user instances.
      */
-    loadPinKeyboardIfNeeded_: function(users) {
+    initializePinKeyboardStateForUsers_: function(users) {
       for (var i = 0; i < users.length; ++i) {
         var user = users[i];
         if (user.showPin) {
           showPinKeyboardAsync();
-          return;
+        } else {
+          // Disable pin for users which should not be able to access pin. Such
+          // users include those who have not set up pin as those who have not

[jdufault, 2016/10/21 19:09:56]

I'm not sure we need to include a comment here. If you want to keep it, please
cleanup it a little, ie:

  // Disable PIN for users which cannot authenticate with it. For 
  // example, users who have not set up PIN or users who have not
  // entered their account password recently.

This comment explains the user.showPin value - I'm not sure that variable is
confusing, though. If anything, we should be explaining why we want to
explicitly call disableKeyboardForUser, ie, if we do not, then the PIN keyboard
can appear when there are >1 users.

[sammiequon, 2016/10/21 22:07:51]

Done.

+          // entered their password recently.
+          this.disablePinKeyboardForUser(user.username);
         }
       }
     },
 
     /**
      * Loads given users in pod row.
      * @param {array} users Array of user.
      * @param {boolean} showGuest Whether to show guest session button.
      */
     loadUsers: function(users, showGuest) {
       $('pod-row').loadPods(users);
       $('login-header-bar').showGuestButton = showGuest;
       // On Desktop, #login-header-bar has a shadow if there are 8+ profiles.
       if (Oobe.getInstance().displayType == DISPLAY_TYPE.DESKTOP_USER_MANAGER)
         $('login-header-bar').classList.toggle('shadow', users.length > 8);
 
-      this.loadPinKeyboardIfNeeded_(users);
+      this.initializePinKeyboardStateForUsers_(users);
     },
 
     /**
      * Runs app with a given id from the list of loaded apps.
      * @param {!string} app_id of an app to run.
      * @param {boolean=} opt_diagnostic_mode Whether to run the app in
      *     diagnostic mode.  Default is false.
      */
     runAppForTesting: function(app_id, opt_diagnostic_mode) {
       $('pod-row').findAndRunAppForTesting(app_id, opt_diagnostic_mode);
@@ skipping 158 matching lines @@
      * @param {string} userID The user ID of the public session
      * @param {string} locale The locale to which this list of keyboard layouts
      *     applies
      * @param {!Object} list List of available keyboard layouts
      */
     setPublicSessionKeyboardLayouts: function(userID, locale, list) {
       $('pod-row').setPublicSessionKeyboardLayouts(userID, locale, list);
     }
   };
 });