Regression test for issue where Opus DTX status was being forgotten.

webrtc/modules/audio_coding/codecs/opus/audio_encoder_opus.h

Index: webrtc/modules/audio_coding/codecs/opus/audio_encoder_opus.h
diff --git a/webrtc/modules/audio_coding/codecs/opus/audio_encoder_opus.h b/webrtc/modules/audio_coding/codecs/opus/audio_encoder_opus.h
index 367c9b90eae5421424683a8f6ece8f919ed02de8..48fb494dbe180bb7b151c5fe36767c83c84411be 100644
--- a/webrtc/modules/audio_coding/codecs/opus/audio_encoder_opus.h
+++ b/webrtc/modules/audio_coding/codecs/opus/audio_encoder_opus.h
@@ -75,6 +75,7 @@ class AudioEncoderOpus final : public AudioEncoder {
   // being inactive. During that, it still sends 2 packets (one for content, one
   // for signaling) about every 400 ms.
   bool SetDtx(bool enable) override;
+  bool GetDtx() const override;
 
   bool SetApplication(Application application) override;
   void SetMaxPlaybackRate(int frequency_hz) override;
@@ -84,7 +85,6 @@ class AudioEncoderOpus final : public AudioEncoder {
   // Getters for testing.
   double packet_loss_rate() const { return packet_loss_rate_; }
   ApplicationMode application() const { return config_.application; }
-  bool dtx_enabled() const { return config_.dtx_enabled; }
 
  protected:
   EncodedInfo EncodeImpl(uint32_t rtp_timestamp,