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

chrome/browser/sync/glue/bookmark_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_BOOKMARK_MODEL_ASSOCIATOR_H_
 #define CHROME_BROWSER_SYNC_GLUE_BOOKMARK_MODEL_ASSOCIATOR_H_
 #pragma once
 
 #include <map>
 #include <set>
@@ skipping 65 matching lines @@
   // Associates the given bookmark node with the given sync id.
   virtual void Associate(const BookmarkNode* node, int64 sync_id);
   // Remove the association that corresponds to the given sync id.
   virtual void Disassociate(int64 sync_id);
 
   virtual void AbortAssociation() {
     // No implementation needed, this associator runs on the main
     // thread.
   }
 
-  // Returns sync service instance.
-  ProfileSyncService* sync_service() { return sync_service_; }
-
  protected:
   // Stores the id of the node with the given tag in |sync_id|.
   // Returns of that node was found successfully.
   // Tests override this.
   virtual bool GetSyncIdForTaggedNode(const std::string& tag, int64* sync_id);
 
+  // Used by TestBookmarkModelAssociator.
+  ProfileSyncService* sync_service() { return sync_service_; }
+
  private:
   typedef std::map<int64, int64> BookmarkIdToSyncIdMap;
   typedef std::map<int64, const BookmarkNode*> SyncIdToBookmarkNodeMap;
   typedef std::set<int64> DirtyAssociationsSyncIds;
 
   // Posts a task to persist dirty associations.
   void PostPersistAssociationsTask();
   // Persists all dirty associations.
   void PersistAssociations();
 
@@ skipping 31 matching lines @@
   ScopedRunnableMethodFactory<BookmarkModelAssociator> persist_associations_;
 
   int number_of_new_sync_nodes_created_at_association_;
 
   DISALLOW_COPY_AND_ASSIGN(BookmarkModelAssociator);
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_GLUE_BOOKMARK_MODEL_ASSOCIATOR_H_