message: Use get_or_create_global_step
diff: @@ -410,7 +410,7 @@ def create_train_op(total_loss,
  loss value.
  """
  if global_step is _USE_GLOBAL_STEP:
  - global_step = training_util.get_global_step()
  + global_step = training_util.get_or_create_global_step()
  # Update ops use GraphKeys.UPDATE_OPS collection if update_ops is None.
  global_update_ops = set(ops.get_collection(ops.GraphKeys.UPDATE_OPS))
  