Handle cases when user cert database has NULL slots

chrome/browser/resources/options/certificate_manager.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.
 
 cr.define('options', function() {
   var OptionsPage = options.OptionsPage;
 
   /////////////////////////////////////////////////////////////////////////////
   // CertificateManagerTab class:
 
@@ skipping 190 matching lines @@
   };
 
   CertificateManager.exportPersonalAskPassword = function(args) {
     CertificateBackupOverlay.show();
   };
 
   CertificateManager.importPersonalAskPassword = function(args) {
     CertificateRestoreOverlay.show();
   };
 
-  CertificateManager.onModelReady = function(tpm_available) {
-    if (tpm_available)
+  CertificateManager.onModelReady = function(userDbAvailable,
+                                             tpmAvailable) {
+    if (!userDbAvailable)
+      return;
+    if (tpmAvailable)
       $('personalCertsTab-import-and-bind').disabled = false;
     $('personalCertsTab-import').disabled = false;
     $('serverCertsTab-import').disabled = false;
     $('caCertsTab-import').disabled = false;
   };
 
   // Export
   return {
     CertificateManagerTab: CertificateManagerTab,
     CertificateManager: CertificateManager
   };
 });