The WebURLResponse will be null if the network request fails. So, a null che...

webkit/glue/alt_error_page_resource_fetcher.cc

 // Copyright (c) 2006-2008 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 "config.h"
 
 #include "base/compiler_specific.h"
 
 MSVC_PUSH_WARNING_LEVEL(0);
 #include "ResourceResponse.h"
@@ skipping 35 matching lines @@
 AltErrorPageResourceFetcher::~AltErrorPageResourceFetcher() {
 }
 
 void AltErrorPageResourceFetcher::OnURLFetchComplete(
     const WebURLResponse& response,
     const std::string& data) {
   WebViewDelegate* delegate = web_view_->GetDelegate();
   if (!delegate)
     return;
 
-  if (response.httpStatusCode() == 200) {
+  if (!response.isNull() && response.httpStatusCode() == 200) {
     // We successfully got a response from the alternate error page server, so
     // load it.
     delegate->LoadNavigationErrorPage(web_frame_, failed_request_,
                                       web_error_, data, true);
   } else {
     delegate->LoadNavigationErrorPage(web_frame_, failed_request_,
                                       web_error_, std::string(), true);
   }
 }
 
-}  // namespace webkit_glue
+}  // namespace webkit_glue