[USS] Implement ApplySyncChanges and OnURLVisited/Modified/Deleted.

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 379 matching lines @@
 
   virtual bool RemoveVisits(const VisitVector& visits);
 
   // Returns the VisitSource associated with each one of the passed visits.
   // If there is no entry in the map for a given visit, that means the visit
   // was SOURCE_BROWSED. Returns false if there is no HistoryDatabase..
   bool GetVisitsSource(const VisitVector& visits, VisitSourceMap* sources);
 
   virtual bool GetURL(const GURL& url, URLRow* url_row);
 
+  bool GetURLByID(URLID url_id, URLRow* url_row);
+
   // Returns the syncable service for syncing typed urls. The returned service
   // is owned by |this| object.
   virtual TypedUrlSyncableService* GetTypedUrlSyncableService() const;
 
   // Returns the sync bridge for syncing typed urls. The returned service
   // is owned by |this| object.
   TypedURLSyncBridge* GetTypedURLSyncBridge() const;
 
   // Deleting ------------------------------------------------------------------
 
@@ skipping 510 matching lines @@
   // it unregisters itself as observer during destruction.
   std::unique_ptr<TypedUrlSyncableService> typed_url_syncable_service_;
   std::unique_ptr<TypedURLSyncBridge> typed_url_sync_bridge_;
 
   DISALLOW_COPY_AND_ASSIGN(HistoryBackend);
 };
 
 }  // namespace history
 
 #endif  // COMPONENTS_HISTORY_CORE_BROWSER_HISTORY_BACKEND_H_