Rounding accuracy for L1/L2 losses: round down the predictions to ints.

def rounding_accuracy(predictions,
                      labels,
                      weights_fn=common_layers.weights_nonzero):
  """Rounding accuracy for L1/L2 losses: round down the predictions to ints."""
  outputs = tf.squeeze(tf.to_int32(predictions))
  labels = tf.squeeze(labels)
  weights = weights_fn(labels)
  labels = tf.to_int32(labels)
  return tf.to_float(tf.equal(outputs, labels)), weights