message: Refinements to PR it is totally fine to create variables outside
  call_for_each_replica, and call_for_each_tower is about to be replaced by
  call_for_each_replcia.
diff: @@ -86,8 +86,7 @@ class ParameterServerStrategyTestBase(
  config=sess_config) as sess, \
  d.scope():
  - # Define a variable outside the call_for_each_replica scope. This is not
  - # recommended.
  + # Define a variable outside the call_for_each_replica scope.
  n = variable_scope.get_variable('n', initializer=10.0)
  self.assertEqual(n.device, '/job:ps/task:0')
  @@ -232,7 +231,7 @@ class ParameterServerStrategyTestBase(
  return x_add, y_add
  - x, y = d.call_for_each_tower(model_fn)
  + x, y = d.call_for_each_replica(model_fn)
  if context.num_gpus() >= 1:
  variables.global_variables_initializer().run()
  