Create an AutofillBackend interface

components/webdata/common/web_database_service.h

 // Copyright 2013 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.
 
 // Chromium settings and storage represent user-selected preferences and
 // information and MUST not be extracted, overwritten or modified except
 // through Chromium defined APIs.
 
 #ifndef COMPONENTS_WEBDATA_COMMON_WEB_DATABASE_SERVICE_H_
 #define COMPONENTS_WEBDATA_COMMON_WEB_DATABASE_SERVICE_H_
@@ skipping 53 matching lines @@
   // the status of the DB after the init.
   virtual void LoadDatabase();
 
   // Unloads the database without actually shutting down the service.  This can
   // be used to temporarily reduce the browser process' memory footprint.
   virtual void UnloadDatabase();
 
   // Unloads database and will not reload.
   virtual void ShutdownDatabase();
 
-  // Gets a ptr to the WebDatabase (owned by WebDatabaseService).
+  // Gets a pointer to the WebDatabase (owned by WebDatabaseService).
   // TODO(caitkp): remove this method once SyncServices no longer depend on it.
   virtual WebDatabase* GetDatabaseOnDB() const;
 
+  // Returns a pointer to the WebDataServiceBackend (owned by
+  // WebDatabaseService).
+  virtual scoped_refptr<WebDataServiceBackend> GetBackend() const;

[Ilya Sherman, 2013/05/08 00:39:06]

nit: Why is this method virtual?

[Cait (Slow), 2013/05/08 19:16:01]

Done.

+
   // Schedule an update/write task on the DB thread.
   virtual void ScheduleDBTask(
       const tracked_objects::Location& from_here,
       const WriteTask& task);
 
   // Schedule a read task on the DB thread.
   virtual WebDataServiceBase::Handle ScheduleDBTaskWithResult(
       const tracked_objects::Location& from_here,
       const ReadTask& task,
       WebDataServiceConsumer* consumer);
@@ skipping 26 matching lines @@
   // PostTask on DB thread may outlive us.
   scoped_refptr<WebDataServiceBackend> wds_backend_;
 
   ObserverList<WebDatabaseObserver> observer_list_;
 
   // All vended weak pointers are invalidated in ShutdownDatabase().
   base::WeakPtrFactory<WebDatabaseService> weak_ptr_factory_;
 };
 
 #endif  // COMPONENTS_WEBDATA_COMMON_WEB_DATABASE_SERVICE_H_