Fix crash in WizardController for Active Directory devices

chrome/browser/chromeos/login/wizard_controller.cc

 // 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.
 
 #include "chrome/browser/chromeos/login/wizard_controller.h"
 
 #include <signal.h>
 #include <stddef.h>
 #include <stdlib.h>
 #include <sys/types.h>
@@ skipping 131 matching lines @@
 }
 
 bool IsRemoraRequisition() {
   return g_browser_process->platform_part()
       ->browser_policy_connector_chromeos()
       ->GetDeviceCloudPolicyManager()
       ->IsRemoraRequisition();
 }
 
 bool IsSharkRequisition() {
-  return g_browser_process->platform_part()
-      ->browser_policy_connector_chromeos()
-      ->GetDeviceCloudPolicyManager()
-      ->IsSharkRequisition();
+  policy::DeviceCloudPolicyManagerChromeOS* policy_manager =
+      g_browser_process->platform_part()
+          ->browser_policy_connector_chromeos()
+          ->GetDeviceCloudPolicyManager();
+  return policy_manager && policy_manager->IsSharkRequisition();
 }
 
 // Checks if a controller device ("Master") is detected during the bootstrapping
 // or shark/remora setup process.
 bool IsControllerDetected() {
   return g_browser_process->local_state()->GetBoolean(
       prefs::kOobeControllerDetected);
 }
 
 void SetControllerDetectedPref(bool value) {
@@ skipping 1333 matching lines @@
             : policy::EnrollmentConfig::MODE_MANUAL_REENROLLMENT;
   }
 
   EnrollmentScreen* screen = EnrollmentScreen::Get(this);
   screen->SetParameters(effective_config, shark_controller_.get());
   SetStatusAreaVisible(true);
   SetCurrentScreen(screen);
 }
 
 }  // namespace chromeos