Use hi-resolution favicon variants if available.

chrome/browser/favicon/favicon_util.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_FAVICON_FAVICON_UTIL_H_
 #define CHROME_BROWSER_FAVICON_FAVICON_UTIL_H_
 
+#include <vector>
+
 class GURL;
 
 namespace content {
 class RenderViewHost;
 }
 
 // Utility class for common favicon related code.
 class FaviconUtil {
  public:
   // Starts the download of the given favicon |url| from the given render view
   // host. When the download is finished, an IconHostMsg_DidDownloadFavicon IPC
   // message will be sent.
   // Returns the unique id of the download request. The id will be sent in the
   // IPC message.
   static int DownloadFavicon(content::RenderViewHost* rvh,
                              const GURL& url,
-                             int image_size);
+                             std::vector<int> image_sizes);
 };
 
 #endif  // CHROME_BROWSER_FAVICON_FAVICON_UTIL_H_