[SyncFS] Wire up MetadataDatabaseIndex to MetadataDatabase

chrome/browser/sync_file_system/drive_backend/metadata_database_index.h

 // Copyright 2014 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_FILE_SYSTEM_DRIVE_BACKEND_METADATA_DATABASE_INDEX_H_
 #define CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_METADATA_DATABASE_INDEX_H_
 
 #include "base/containers/hash_tables.h"
 #include "base/containers/scoped_ptr_hash_map.h"
 #include "chrome/browser/sync_file_system/drive_backend/metadata_database.h"
@@ skipping 109 matching lines @@
   typedef base::ScopedPtrHashMap<int64, FileTracker> TrackerByID;
   typedef base::hash_map<std::string, TrackerIDSet> TrackerIDsByFileID;
   typedef base::hash_map<std::string, TrackerIDSet> TrackerIDsByTitle;
   typedef std::map<int64, TrackerIDsByTitle> TrackerIDsByParentAndTitle;
   typedef base::hash_map<std::string, int64> TrackerIDByAppID;
   typedef base::hash_set<std::string> FileIDSet;
   typedef base::hash_set<ParentIDAndTitle> PathSet;
   typedef std::set<int64> DirtyTrackers;
 
   friend class MetadataDatabase;
+  friend class MetadataDatabaseTest;
 
   // Maintains |app_root_by_app_id_|.
   void AddToAppIDIndex(const FileTracker& new_tracker);
   void UpdateInAppIDIndex(const FileTracker& old_tracker,
                           const FileTracker& new_tracker);
   void RemoveFromAppIDIndex(const FileTracker& tracker);
 
   // Maintains |trackers_by_file_id_| and |multi_tracker_file_ids_|.
   void AddToFileIDIndexes(const FileTracker& new_tracker);
   void UpdateInFileIDIndexes(const FileTracker& old_tracker,
@@ skipping 26 matching lines @@
   DirtyTrackers dirty_trackers_;
   DirtyTrackers demoted_dirty_trackers_;
 
   DISALLOW_COPY_AND_ASSIGN(MetadataDatabaseIndex);
 };
 
 }  // namespace drive_backend
 }  // namespace sync_file_system
 
 #endif  // CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_METADATA_DATABASE_INDEX_H_