Extend HistoryService with support for favicons from Google servers

components/history/core/browser/history_service.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_SERVICE_H_
 #define COMPONENTS_HISTORY_CORE_BROWSER_HISTORY_SERVICE_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 743 matching lines @@
   // |page_url| for |icon_type|.
   // Use MergeFavicon() if |bitmaps| is incomplete, and favicon bitmaps in the
   // database should be preserved if possible. For instance, favicon bitmaps
   // from sync are 1x only. MergeFavicon() is used to avoid deleting the 2x
   // favicon bitmap if it is present in the history backend.
   void SetFavicons(const GURL& page_url,
                    favicon_base::IconType icon_type,
                    const GURL& icon_url,
                    const std::vector<SkBitmap>& bitmaps);
 
+  // Same as SetFavicons with three differences:
+  // 1) It will be a no-op if there is an existing cached favicon for *any* type
+  //    for |page_url|.
+  // 2) If |icon_url| is known to the database, |bitmaps| will be ignored (i.e.
+  //    the icon won't be overwritten) but the mappings from |page_url| to
+  //    |icon_url| will be stored (conditioned to point 1 above).
+  // 3) If |icon_url| is stored, it will be marked as expired.
+  // The callback will receive whether the write actually happened.
+  void SetLastResortFavicons(const GURL& page_url,
+                             favicon_base::IconType icon_type,
+                             const GURL& icon_url,
+                             const std::vector<SkBitmap>& bitmaps,
+                             base::Callback<void(bool)> callback);
+
   // Used by the FaviconService to mark the favicon for the page as being out
   // of date.
   void SetFaviconsOutOfDateForPage(const GURL& page_url);
 
   // Used by the FaviconService for importing many favicons for many pages at
   // once. The pages must exist, any favicon sets for unknown pages will be
   // discarded. Existing favicons will not be overwritten.
   void SetImportedFavicons(
       const favicon_base::FaviconUsageDataList& favicon_usage);
 
@@ skipping 62 matching lines @@
 
   // All vended weak pointers are invalidated in Cleanup().
   base::WeakPtrFactory<HistoryService> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(HistoryService);
 };
 
 }  // namespace history
 
 #endif  // COMPONENTS_HISTORY_CORE_BROWSER_HISTORY_SERVICE_H_