Using AudioOption to enable audio network adaptor.

webrtc/media/base/mediachannel.h

Index: webrtc/media/base/mediachannel.h
diff --git a/webrtc/media/base/mediachannel.h b/webrtc/media/base/mediachannel.h
index 781a46d90c63122bc6504ca02f97cf3ecefa742a..e57cab1c7a0bba5a5bfa698b5a910ef114b34dcc 100644
--- a/webrtc/media/base/mediachannel.h
+++ b/webrtc/media/base/mediachannel.h
@@ -168,6 +168,7 @@ struct AudioOptions {
     SetFrom(&recording_sample_rate, change.recording_sample_rate);
     SetFrom(&playout_sample_rate, change.playout_sample_rate);
     SetFrom(&combined_audio_video_bwe, change.combined_audio_video_bwe);
+    SetFrom(&audio_network_adaptor_config, change.audio_network_adaptor_config);
   }
 
   bool operator==(const AudioOptions& o) const {
@@ -195,7 +196,8 @@ struct AudioOptions {
            tx_agc_limiter == o.tx_agc_limiter &&
            recording_sample_rate == o.recording_sample_rate &&
            playout_sample_rate == o.playout_sample_rate &&
-           combined_audio_video_bwe == o.combined_audio_video_bwe;
+           combined_audio_video_bwe == o.combined_audio_video_bwe &&
+           audio_network_adaptor_config == o.audio_network_adaptor_config;
   }
   bool operator!=(const AudioOptions& o) const { return !(*this == o); }
 
@@ -227,6 +229,8 @@ struct AudioOptions {
     ost << ToStringIfSet("recording_sample_rate", recording_sample_rate);
     ost << ToStringIfSet("playout_sample_rate", playout_sample_rate);
     ost << ToStringIfSet("combined_audio_video_bwe", combined_audio_video_bwe);
+    ost << ToStringIfSet("audio_network_adaptor_config",
+                         audio_network_adaptor_config);
     ost << "}";
     return ost.str();
   }
@@ -267,6 +271,8 @@ struct AudioOptions {
   // "googCombinedAudioVideoBwe", but not used anywhere. So delete it,
   // and check if any other AudioOptions members are unused.
   rtc::Optional<bool> combined_audio_video_bwe;
+  // Enable audio network adaptor and its config string.
+  rtc::Optional<std::string> audio_network_adaptor_config;
 
  private:
   template <typename T>