message: Don't use session context manager when we need session to outlive the context block.
diff: @@ -466,7 +466,7 @@ def model_to_estimator(keras_model=None,
  keras_model_fn, model_dir=model_dir, config=config)
  # Pass the config into keras backend's default session.
  - with session.Session(config=estimator._session_config) as sess:
  + sess = session.Session(config=estimator._session_config)
  K.set_session(sess)
  keras_weights = keras_model.get_weights()
  