Extend LargeIconService to fetch missing favicons from a Google server

components/history/core/browser/history_backend.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 COMPONENTS_HISTORY_CORE_BROWSER_HISTORY_BACKEND_H_
 #define COMPONENTS_HISTORY_CORE_BROWSER_HISTORY_BACKEND_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 302 matching lines @@
       int icon_types,
       const std::vector<int>& desired_sizes,
       std::vector<favicon_base::FaviconRawBitmapResult>* bitmap_results);
 
   void MergeFavicon(const GURL& page_url,
                     const GURL& icon_url,
                     favicon_base::IconType icon_type,
                     scoped_refptr<base::RefCountedMemory> bitmap_data,
                     const gfx::Size& pixel_size);
 
-  void SetFavicons(const GURL& page_url,
-                   favicon_base::IconType icon_type,
-                   const GURL& icon_url,
-                   const std::vector<SkBitmap>& bitmaps);
+  favicon_base::FaviconID SetFavicons(const GURL& page_url,
+                                      favicon_base::IconType icon_type,
+                                      const GURL& icon_url,
+                                      const std::vector<SkBitmap>& bitmaps);
+
+  void SetExpiredFaviconsIfNoneKnown(const GURL& page_url,
+                                     favicon_base::IconType icon_type,
+                                     const GURL& icon_url,
+                                     const std::vector<SkBitmap>& bitmaps);
 
   void SetFaviconsOutOfDateForPage(const GURL& page_url);
 
   void SetImportedFavicons(
       const favicon_base::FaviconUsageDataList& favicon_usage);
 
   // Downloads -----------------------------------------------------------------
 
   uint32_t GetNextDownloadId();
   void QueryDownloads(std::vector<DownloadRow>* rows);
@@ skipping 553 matching lines @@
   // Init is called. Defined after observers_ because it unregisters itself as
   // observer during destruction.
   std::unique_ptr<TypedUrlSyncableService> typed_url_syncable_service_;
 
   DISALLOW_COPY_AND_ASSIGN(HistoryBackend);
 };
 
 }  // namespace history
 
 #endif  // COMPONENTS_HISTORY_CORE_BROWSER_HISTORY_BACKEND_H_