Don't request missing favicon on every page request.

chrome/browser/ui/metro_pin_tab_helper_win.cc

 // 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.
 
 #include "chrome/browser/ui/metro_pin_tab_helper_win.h"
 
 #include <set>
 
 #include "base/base_paths.h"
 #include "base/bind.h"
@@ skipping 410 matching lines @@
 }
 
 void MetroPinTabHelper::DidUpdateFaviconURL(
     int32 page_id,
     const std::vector<content::FaviconURL>& candidates) {
   favicon_url_candidates_ = candidates;
 }
 
 void MetroPinTabHelper::DidDownloadFavicon(
     int id,
+    int http_status_code,
     const GURL& image_url,
     int requested_size,
     const std::vector<SkBitmap>& bitmaps) {
   if (favicon_chooser_.get()) {
     favicon_chooser_->UpdateCandidate(id, image_url, requested_size, bitmaps);
   }
 }
 
 void MetroPinTabHelper::UnPinPageFromStartScreen() {
   HMODULE metro_module = base::win::GetMetroModule();
@@ skipping 10 matching lines @@
 
   GURL url = web_contents()->GetURL();
   string16 tile_id = GenerateTileId(UTF8ToUTF16(url.spec()));
   metro_un_pin_from_start_screen(tile_id,
                                  base::Bind(&PinPageReportUmaCallback));
 }
 
 void MetroPinTabHelper::FaviconDownloaderFinished() {
   favicon_chooser_.reset();
 }