message: Use `strategy.make_input_fn_iterator` in estimator instead of the
  deprecated `strategy.distribute_dataset`.
diff: @@ -303,6 +303,20 @@ class TPUExtended(distribute_lib.DistributionStrategyExtended):
  functools.partial(self._call_dataset_fn, dataset_fn),
  self._input_workers)
  + def _make_input_fn_iterator(
  + self,
  + input_fn,
  + replication_mode=distribute_lib.InputReplicationMode.PER_WORKER):
  + input_contexts = []
  + num_workers = self._input_workers.num_workers
  + for i in range(num_workers):
  + input_contexts.append(distribute_lib.InputContext(
  + num_input_pipelines=num_workers,
  + input_pipeline_id=i,
  + num_replicas_in_sync=self._num_replicas_in_sync))
  + return input_lib.InputFunctionIterator(
  + input_fn, self._input_workers, input_contexts)
  +
  def _experimental_make_numpy_dataset(self, numpy_input, session):
  return numpy_dataset.one_host_numpy_dataset(
  numpy_input, numpy_dataset.SingleDevice(self.get_host_cpu_device(0)),
  