message: Handle the case when value_destination_pairs is zip in cross_device_ops
diff: @@ -116,6 +116,9 @@ def _make_tensor_into_per_replica(input_tensor):
  def _normalize_value_destination_pairs(value_destination_pairs):
  """Converts each tensor into a PerReplica object in the input list."""
  result = []
  +
  + value_destination_pairs = list(value_destination_pairs)
  +
  if not isinstance(value_destination_pairs, (list, tuple)):
  raise ValueError("`value_destination_pairs` should be a list or tuple")
  for pair in value_destination_pairs:
  