SyncServiceObserver 171 chrome/browser/sync_file_system/drive_backend/sync_engine.cc void SyncEngine::AddServiceObserver(SyncServiceObserver* observer) { SyncServiceObserver 83 chrome/browser/sync_file_system/drive_backend/sync_engine.h virtual void AddServiceObserver(SyncServiceObserver* observer) OVERRIDE; SyncServiceObserver 204 chrome/browser/sync_file_system/drive_backend/sync_engine.h ObserverList<SyncServiceObserver> service_observers_;