message: Make Per-Host input_fn deployment as default (instead of Per-Core)
diff: @@ -42,17 +42,16 @@ class TPUConfig(
  is invoked once on each host. To be precise, with a global batch size
  `train_batch_size` in `TPUEstimator` constructor, the batch size for each
  shard is `train_batch_size` // #hosts. With Per-Core input pipeline
  - deployment, the shard batch size is `train_batch_size` // #cores. Note:
  - This behavior is going to be default as `True` soon, so this flag will be
  - removed after that. Also note that this only works for single-host TPU
  - training now (tracked in b/67051042). For multi-host, please use Per-Core,
  - i.e., `False` for `per_host_input_for_training`.
  + deployment, the shard batch size is `train_batch_size` // #cores. Note
  + that this only works for single-host TPU training now (tracked in
  + b/67051042). For multi-host, please use Per-Core, i.e., `False` for
  + `per_host_input_for_training`.
  """
  def __new__(cls,
  iterations_per_loop=2,
  num_shards=2,
  - per_host_input_for_training=False):
  + per_host_input_for_training=True):
  # Check iterations_per_loop.
  util_lib.check_positive_integer(iterations_per_loop,
  