[Sync] Refactored ProfileSyncService and remove its backend() function

chrome/browser/sync/glue/autofill_model_associator.h

 // Copyright (c) 2010 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_SYNC_GLUE_AUTOFILL_MODEL_ASSOCIATOR_H_
 #define CHROME_BROWSER_SYNC_GLUE_AUTOFILL_MODEL_ASSOCIATOR_H_
 #pragma once
 
 #include <map>
 #include <set>
@@ skipping 81 matching lines @@
   static bool MergeTimestamps(const sync_pb::AutofillSpecifics& autofill,
                               const std::vector<base::Time>& timestamps,
                               std::vector<base::Time>* new_timestamps);
   static bool FillProfileWithServerData(
       AutoFillProfile* merge_into,
       const sync_pb::AutofillProfileSpecifics& specifics);
 
   // TODO(georgey) : add the same processing for CC info (already in protocol
   // buffers).
 
-  // Returns sync service instance.
-  ProfileSyncService* sync_service() { return sync_service_; }
-
   // Is called to determine if we need to upgrade to the new
   // autofillprofile2 data type. If so we need to sync up autofillprofile
   // first to the latest available changes on the server and then upgrade
   // to autofillprofile2.
   virtual bool HasNotMigratedYet(const sync_api::BaseTransaction* trans);
 
  protected:
   // Given a profile from sync db it tries to match the profile against
   // one in web db. it ignores the guid and compares the actual data.
   AutoFillProfile* FindCorrespondingNodeFromWebDB(
@@ skipping 71 matching lines @@
   base::Lock abort_association_pending_lock_;
   bool abort_association_pending_;
   int number_of_entries_created_;
 
   DISALLOW_COPY_AND_ASSIGN(AutofillModelAssociator);
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_GLUE_AUTOFILL_MODEL_ASSOCIATOR_H_