Coverity: check null returns.

chrome/browser/policy/configuration_policy_handler.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/policy/configuration_policy_handler.h"
 
 #include <string>
 
 #include "base/file_path.h"
 #include "base/json/json_writer.h"
@@ skipping 723 matching lines @@
 
   switch (proxy_mode) {
     case ProxyPrefs::MODE_DIRECT:
       prefs->SetValue(prefs::kProxy, ProxyConfigDictionary::CreateDirect());
       break;
     case ProxyPrefs::MODE_AUTO_DETECT:
       prefs->SetValue(prefs::kProxy, ProxyConfigDictionary::CreateAutoDetect());
       break;
     case ProxyPrefs::MODE_PAC_SCRIPT: {
       std::string pac_url_string;
-      if (pac_url->GetAsString(&pac_url_string)) {
+      if (pac_url && pac_url->GetAsString(&pac_url_string)) {
         prefs->SetValue(prefs::kProxy,
             ProxyConfigDictionary::CreatePacScript(pac_url_string, false));
       } else {
         NOTREACHED();
       }
       break;
     }
     case ProxyPrefs::MODE_FIXED_SERVERS: {
       std::string proxy_server;
       std::string bypass_list_string;
@@ skipping 243 matching lines @@
         errors->AddError(key::kClearSiteDataOnExit,
                          IDS_POLICY_OVERRIDDEN,
                          key::kRestoreOnStartup);
       }
     }
   }
   return true;
 }
 
 }  // namespace policy