message: Make optimize_for_inference_test.py work the C API enabled.
diff: @@ -29,6 +29,7 @@ from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import importer
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import tensor_util
  +from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import gen_nn_ops
  from tensorflow.python.ops import image_ops
  @@ -38,6 +39,7 @@ from tensorflow.python.platform import test
  from tensorflow.python.tools import optimize_for_inference_lib
  +@test_util.with_c_api
  class OptimizeForInferenceTest(test.TestCase):
  def create_node_def(self, op, name, inputs):
  @@ -145,7 +147,7 @@ class OptimizeForInferenceTest(test.TestCase):
  np.array([0.1, 0.6]), shape=[2], dtype=dtypes.float32)
  gamma_op = constant_op.constant(
  np.array([1.0, 2.0]), shape=[2], dtype=dtypes.float32)
  - ops.get_default_graph().graph_def_versions.producer = 8
  + test_util.set_producer_version(ops.get_default_graph(), 8)
  gen_nn_ops._batch_norm_with_global_normalization(
  conv_op,
  mean_op,
  