Don't request missing favicon on every page request.

chrome/browser/ui/metro_pin_tab_helper_win.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 CHROME_BROWSER_UI_METRO_PIN_TAB_HELPER_WIN_H_
 #define CHROME_BROWSER_UI_METRO_PIN_TAB_HELPER_WIN_H_
 
 #include <vector>
 
 #include "content/public/browser/web_contents_observer.h"
@@ skipping 25 matching lines @@
   // The FaviconDownloader class handles downloading the favicons when a page
   // is being pinned. After it has downloaded any available favicons it will
   // continue on with the page pinning action.
   class FaviconChooser;
 
   explicit MetroPinTabHelper(content::WebContents* web_contents);
   friend class content::WebContentsUserData<MetroPinTabHelper>;
 
   // Favicon download callback.
   void DidDownloadFavicon(int id,
+                          int http_status_code,
                           const GURL& image_url,
                           int requested_size,
                           const std::vector<SkBitmap>& bitmaps);
 
   void UnPinPageFromStartScreen();
 
   // Called by the |favicon_chooser_| when it has finished.
   void FaviconDownloaderFinished();
 
   // Candidate Favicon URLs for the current page.
   std::vector<content::FaviconURL> favicon_url_candidates_;
 
   // The currently active FaviconChooser, if there is one.
   scoped_ptr<FaviconChooser> favicon_chooser_;
 
 
   DISALLOW_COPY_AND_ASSIGN(MetroPinTabHelper);
 };
 
 #endif  // CHROME_BROWSER_UI_METRO_PIN_TAB_HELPER_WIN_H_