root/sync/internal_api/public/engine/

[..]
  1. model_safe_worker.cc
  2. model_safe_worker.h
  3. model_safe_worker_unittest.cc
  4. passive_model_worker.cc
  5. passive_model_worker.h
  6. polling_constants.cc
  7. polling_constants.h
  8. sync_status.cc
  9. sync_status.h
[..]