message: TPU internal code update.
diff: @@ -21,7 +21,7 @@ limitations under the License.
  namespace tensorflow {
  namespace tpu {
  std::shared_ptr<::grpc::ChannelCredentials> CreateChannelCredentials() {
  - return ::grpc::InsecureChannelCredentials();
  + return ::grpc::InsecureChannelCredentials(); // NOLINT
  }
  #if defined(LIBTFTPU)
  