Add error description to the DidFailProvisionalLoad callback.

chrome/renderer/localized_error.h

 // 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.
 
 #ifndef CHROME_RENDERER_LOCALIZED_ERROR_H_
 #define CHROME_RENDERER_LOCALIZED_ERROR_H_
 #pragma once
 
 #include <string>
 
 #include "base/basictypes.h"
+#include "base/string16.h"
 
 class Extension;
 class GURL;
 
 namespace base {
 class DictionaryValue;
 }
 
 namespace WebKit {
 struct WebURLError;
 }
 
 class LocalizedError {
  public:
   // Fills |error_strings| with values to be used to build an error page used
   // on HTTP errors, like 404 or connection reset.
   static void GetStrings(const WebKit::WebURLError& error,
                          base::DictionaryValue* strings);
 
+  // Returns a description of the encountered error.
+  static string16 GetErrorDetails(const WebKit::WebURLError& error);
+
   // Returns true if an error page exists for the specified parameters.
   static bool HasStrings(const std::string& error_domain, int error_code);
 
   // Fills |error_strings| with values to be used to build an error page which
   // warns against reposting form data. This is special cased because the form
   // repost "error page" has no real error associated with it, and doesn't have
   // enough strings localized to meaningfully fill the net error template.
   static void GetFormRepostStrings(const GURL& display_url,
                                    base::DictionaryValue* error_strings);
 
   // Fills |error_strings| with values to be used to build an error page used
   // on HTTP errors, like 404 or connection reset, but using information from
   // the associated |app| in order to make the error page look like it's more
   // part of the app.
   static void GetAppErrorStrings(const WebKit::WebURLError& error,
                                  const GURL& display_url,
                                  const Extension* app,
                                  base::DictionaryValue* error_strings);
 
   static const char kHttpErrorDomain[];
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(LocalizedError);
 };
 
 #endif  // CHROME_RENDERER_LOCALIZED_ERROR_H_