[Android WebView] Implement a better OnReceivedError callback

android_webview/browser/aw_contents_io_thread_client.h

 // 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.
 
 #ifndef ANDROID_WEBVIEW_BROWSER_AW_CONTENTS_IO_THREAD_CLIENT_H_
 #define ANDROID_WEBVIEW_BROWSER_AW_CONTENTS_IO_THREAD_CLIENT_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 86 matching lines @@
                            const std::string& mime_type,
                            int64 content_length) = 0;
 
   // Called when a new login request is detected. See the documentation for
   // WebViewClient.onReceivedLoginRequest for arguments. Note that |account|
   // may be empty.
   virtual void NewLoginRequest(const std::string& realm,
                                const std::string& account,
                                const std::string& args) = 0;
 
+  // Called when a resource loading error has occured (e.g. an I/O error,
+  // host name lookup failure etc.)
+  virtual void OnReceivedError(const net::URLRequest* request) = 0;
+
   // Called when a response from the server is received with status code >= 400.
   virtual void OnReceivedHttpError(
       const net::URLRequest* request,
       const net::HttpResponseHeaders* response_headers) = 0;
 };
 
 } // namespace android_webview
 
 #endif  // ANDROID_WEBVIEW_BROWSER_AW_CONTENTS_IO_THREAD_CLIENT_H_