[Favicon] Stop caching the default favicon

chrome/browser/ui/webui/favicon_source.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_WEBUI_FAVICON_SOURCE_H_
 #define CHROME_BROWSER_UI_WEBUI_FAVICON_SOURCE_H_
 
 #include <map>
 #include <string>
 
@@ skipping 109 matching lines @@
 
   // Sends the 16x16 DIP 1x default favicon.
   void SendDefaultResponse(
       const content::URLDataSource::GotDataCallback& callback);
 
   // Sends the default favicon.
   void SendDefaultResponse(const IconRequest& request);
 
   base::CancelableTaskTracker cancelable_task_tracker_;
 
-  // Raw PNG representations of favicons of each size to show when the favicon
-  // database doesn't have a favicon for a webpage. Indexed by IconSize values.
-  scoped_refptr<base::RefCountedMemory> default_favicons_[NUM_SIZES];
-
   // The favicon_base::IconTypes of icon that this FaviconSource handles.
   int icon_types_;
 
   DISALLOW_COPY_AND_ASSIGN(FaviconSource);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_FAVICON_SOURCE_H_