cros: Load pin assets on sign-in screen.

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

Index: chrome/browser/resources/chromeos/login/md_login.js
diff --git a/chrome/browser/resources/chromeos/login/md_login.js b/chrome/browser/resources/chromeos/login/md_login.js
index cc899d30eee5b2be91ff2f8ec8b88b9073dec5cb..e4e4e7dc80e3a86d605a8825ef92eb2c824a7254 100644
--- a/chrome/browser/resources/chromeos/login/md_login.js
+++ b/chrome/browser/resources/chromeos/login/md_login.js
@@ -12,6 +12,17 @@ var isMd = true;
 // <include src="login_non_lock_shared.js">
 // <include src="notification_card.js">
 
+/**
+ * Ensures that the pin keyboard is loaded.
+ * @param {object} onLoaded Callback executed when the pin keyboard is loaded.
+ */
+function ensurePinKeyboardLoaded(onLoaded) {
+  'use strict';
+
+  // Wait a frame before running |onLoaded| to avoid any visual glitches.
+  setTimeout(onLoaded);
+}
+
 cr.define('cr.ui.Oobe', function() {
   return {
     /**