[SyncFS] Drop test only un-thread-safe getters from SyncEngine (4)

chrome/browser/sync_file_system/drive_backend/sync_engine_context.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.
 
 #ifndef CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_SYNC_ENGINE_CONTEXT_H_
 #define CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_SYNC_ENGINE_CONTEXT_H_
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 41 matching lines @@
   RemoteChangeProcessor* GetRemoteChangeProcessor();
   base::SingleThreadTaskRunner* GetUITaskRunner();
   base::SequencedTaskRunner* GetWorkerTaskRunner();
   base::SequencedTaskRunner* GetFileTaskRunner();
 
   scoped_ptr<MetadataDatabase> PassMetadataDatabase();
 
   void DetachFromSequence();
 
  private:
+  friend class DriveBackendSyncTest;
+
   scoped_ptr<drive::DriveServiceInterface> drive_service_;
   scoped_ptr<drive::DriveUploaderInterface> drive_uploader_;
   base::WeakPtr<TaskLogger> task_logger_;
   RemoteChangeProcessor* remote_change_processor_;  // Not owned.
 
   scoped_ptr<MetadataDatabase> metadata_database_;
   scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner_;
   scoped_refptr<base::SequencedTaskRunner> worker_task_runner_;
   scoped_refptr<base::SequencedTaskRunner> file_task_runner_;
 
   base::SequenceChecker sequence_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncEngineContext);
 };
 
 }  // namespace drive_backend
 }  // namespace sync_file_system
 
 #endif  // CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_SYNC_ENGINE_CONTEXT_H_