Enable the PIN keyboard on the lockscreen.

chrome/browser/resources/chromeos/login/lock.js

 // Copyright (c) 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 Login UI based on a stripped down OOBE controller.
  */
 
 <include src="login_shared.js">
 
-// Lazy load polymer.
-(function() {
+// Asynchronously loads the pin keyboard.
+function showPinKeyboardAsync() {
   'use strict';
 
+  // This function could get called multiple times. Do nothing if we have
+  // already loaded. This check needs to happen before the registerAssets call,
+  // because that will clobber the loaded state.
+  if (cr.ui.login.ResourceLoader.alreadyLoadedAssets('custom-elements'))
+    return;
+
   // Register loader for custom elements.
   cr.ui.login.ResourceLoader.registerAssets({
     id: 'custom-elements',
     html: [{ url: 'chrome://oobe/custom_elements.html' }]
   });
 
   // Called after polymer has been loaded. Fades the pin element in.
   var onPinLoaded = function(pinContainer) {
     pinContainer.style.opacity = 1;
   };
 
   // We only load the PIN element when it is actually shown so that lock screen
   // load times remain low when the user is not using a PIN.
   //
   // Loading the PIN element blocks the DOM, which will interrupt any running
   // animations. We load the PIN after an idle notification to allow the pod
   // fly-in animation to complete without interruption.
-  if (loadTimeData.getBoolean('showPin')) {
-    cr.ui.login.ResourceLoader.loadAssetsOnIdle('custom-elements', function() {
-      cr.ui.login.ResourceLoader.waitUntilLayoutComplete('pin-container',
-                                                         onPinLoaded);
-    });
-  }
-})();
+  cr.ui.login.ResourceLoader.loadAssetsOnIdle('custom-elements', function() {
+    cr.ui.login.ResourceLoader.waitUntilLayoutComplete('pin-container',
+                                                       onPinLoaded);
+  });
+}
 
 cr.define('cr.ui.Oobe', function() {
   return {
     /**
      * Initializes the OOBE flow.  This will cause all C++ handlers to
      * be invoked to do final setup.
      */
     initialize: function() {
       // TODO(jdufault): Remove this after resolving crbug.com/452599.
       console.log('Start initializing LOCK OOBE');
@@ skipping 22 matching lines @@
      * Reloads content of the page.
      * @param {!Object} data New dictionary with i18n values.
      */
     reloadContent: function(data) {
       loadTimeData.overrideValues(data);
       i18nTemplate.process(document, loadTimeData);
       Oobe.getInstance().updateLocalizedContent_();
     },
   };
 });