message: Make delegate_ filed accessible from inherited class of tflite_driver.
diff: @@ -65,6 +65,9 @@ class TfLiteDriver : public TestRunner {
  string ReadOutput(int id) override;
  void SetThreshold(double relative_threshold, double absolute_threshold);
  + protected:
  + Interpreter::TfLiteDelegatePtr delegate_;
  +
  private:
  void DeallocateStringTensor(TfLiteTensor* t) {
  if (t) {
  @@ -83,7 +86,6 @@ class TfLiteDriver : public TestRunner {
  class Expectation;
  std::unique_ptr<OpResolver> resolver_;
  - Interpreter::TfLiteDelegatePtr delegate_;
  std::unique_ptr<FlatBufferModel> model_;
  std::unique_ptr<Interpreter> interpreter_;
  std::map<int, std::unique_ptr<Expectation>> expected_output_;
  