message: Fix `TPUStrategy` `num_replicas_in_sync` calculation.
diff: @@ -539,16 +539,13 @@ class TPUExtended(distribute_lib.StrategyExtendedV1):
  # This method needs to take host_id as input for correct computation.
  max_models_per_host = (self._tpu_metadata.num_of_cores_per_host //
  self._device_assignment.num_cores_per_replica)
  - models_per_host = min(self._device_assignment.num_replicas,
  - max_models_per_host)
  - return models_per_host * self._device_assignment.num_cores_per_replica
  + return min(self._device_assignment.num_replicas, max_models_per_host)
  @property
  def _num_replicas_in_sync(self):
  if self._device_assignment is None:
  return self._tpu_metadata.num_cores
  - return (self._device_assignment.num_replicas *
  - self._device_assignment.num_cores_per_replica)
  + return self._device_assignment.num_replicas
  @property
  def experimental_between_graph(self):
  