message: Move global_step_read dependency to model_fn instead of input_fn.
diff: @@ -708,9 +708,9 @@ class Estimator(object):
  random_seed.set_random_seed(self._config.tf_random_seed)
  global_step_tensor = self._create_and_assert_global_step(g)
  global_step_read_tensor = training_util._get_or_create_global_step_read() # pylint: disable=protected-access
  - with ops.control_dependencies([global_step_read_tensor]):
  features, labels = self._get_features_and_labels_from_input_fn(
  input_fn, model_fn_lib.ModeKeys.TRAIN)
  + with ops.control_dependencies([global_step_read_tensor]):
  estimator_spec = self._call_model_fn(
  features, labels, model_fn_lib.ModeKeys.TRAIN, self.config)
  # Check if the user created a loss summary, and add one if they didn't.
  