message: Fix small performance regression in microbenchmarks.
diff: @@ -217,7 +217,8 @@ class MicroBenchmarks(test.Benchmark):
  self._run(f, 30000)
  def benchmark_tf_gradient_function_identity(self):
  - m = self._m_2
  + with context.device(CPU):
  + m = gen_array_ops.identity(self._m_2)
  self._run(
  lambda: backprop.gradients_function(gen_array_ops.identity, [0])(m),
  30000)
  @@ -236,7 +237,8 @@ class MicroBenchmarks(test.Benchmark):
  self._run(f, 30000)
  def benchmark_tf_gradient_function_no_op(self):
  - m = self._m_2
  + with context.device(CPU):
  + m = gen_array_ops.identity(self._m_2)
  self._run(
  lambda: backprop.gradients_function(lambda x: x, [0])(m),
  30000)
  @@ -271,11 +273,12 @@ class MicroBenchmarks(test.Benchmark):
  # pylint: disable=protected-access
  ctx_handle = context.context()._handle
  # pylint: enable=protected-access
  + device = context.context().device_name
  attrs = ("transpose_a", False, "transpose_b", transpose_b, "T",
  m.dtype.as_datatype_enum)
  def func():
  - pywrap_tensorflow.TFE_Py_Execute(ctx_handle, None, "MatMul", inputs,
  - attrs, 1)
  + pywrap_tensorflow.TFE_Py_Execute(ctx_handle, device, "MatMul",
  + inputs, attrs, 1)
  self._run(func, num_iters)
  