Don't request missing favicon on every page request.

chrome/browser/ui/extensions/shell_window.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/extensions/shell_window.h"
 
 #include "base/utf_string_conversions.h"
 #include "base/values.h"
 #include "chrome/browser/extensions/app_window_contents.h"
 #include "chrome/browser/extensions/extension_process_manager.h"
@@ skipping 405 matching lines @@
 }
 
 //------------------------------------------------------------------------------
 // Private methods
 
 void ShellWindow::OnImageLoaded(const gfx::Image& image) {
   UpdateAppIcon(image);
 }
 
 void ShellWindow::DidDownloadFavicon(int id,
+                                     int http_status_code,
                                      const GURL& image_url,
                                      int requested_size,
                                      const std::vector<SkBitmap>& bitmaps) {
   if (image_url != app_icon_url_ || bitmaps.empty())
     return;
 
   // Bitmaps are ordered largest to smallest. Choose the smallest bitmap
   // whose height >= the preferred size.
   int largest_index = 0;
   for (size_t i = 1; i < bitmaps.size(); ++i) {
@@ skipping 154 matching lines @@
     const extensions::DraggableRegion& region = *iter;
     sk_region->op(
         region.bounds.x(),
         region.bounds.y(),
         region.bounds.right(),
         region.bounds.bottom(),
         region.draggable ? SkRegion::kUnion_Op : SkRegion::kDifference_Op);
   }
   return sk_region;
 }