Don't request missing favicon on every page request.

content/browser/web_contents/web_contents_impl.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 CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_IMPL_H_
 #define CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_IMPL_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 565 matching lines @@
                           const base::FilePath& path,
                           bool is_hung);
   void OnWebUISend(const GURL& source_url,
                    const std::string& name,
                    const base::ListValue& args);
   void OnRequestPpapiBrokerPermission(int request_id,
                                       const GURL& url,
                                       const base::FilePath& plugin_path);
   void OnBrowserPluginMessage(const IPC::Message& message);
   void OnDidDownloadImage(int id,
+                          int http_status_code,
                           const GURL& image_url,
                           int requested_size,
                           const std::vector<SkBitmap>& bitmaps);
   void OnUpdateFaviconURL(int32 page_id,
                           const std::vector<FaviconURL>& candidates);
   void OnFrameDetached(int64 frame_id);
 
   // Changes the IsLoading state and notifies delegate as needed
   // |details| is used to provide details on the load that just finished
   // (but can be null if not applicable). Can be overridden.
@@ skipping 299 matching lines @@
   // Maps the ids of pending image downloads to their callbacks
   typedef std::map<int, ImageDownloadCallback> ImageDownloadMap;
   ImageDownloadMap image_download_map_;
 
   DISALLOW_COPY_AND_ASSIGN(WebContentsImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_IMPL_H_