Instantly pass network changes to controllers in audio network adaptor.

webrtc/modules/audio_coding/audio_network_adaptor/bitrate_controller.h

Index: webrtc/modules/audio_coding/audio_network_adaptor/bitrate_controller.h
diff --git a/webrtc/modules/audio_coding/audio_network_adaptor/bitrate_controller.h b/webrtc/modules/audio_coding/audio_network_adaptor/bitrate_controller.h
index a41c5f46fd67a236a0adeed7216d51c851682304..5e03b455bd72a0ed640e33606bc9517b56a7154f 100644
--- a/webrtc/modules/audio_coding/audio_network_adaptor/bitrate_controller.h
+++ b/webrtc/modules/audio_coding/audio_network_adaptor/bitrate_controller.h
@@ -28,13 +28,18 @@ class BitrateController final : public Controller {
 
   explicit BitrateController(const Config& config);
 
-  void MakeDecision(const NetworkMetrics& metrics,
-                    AudioNetworkAdaptor::EncoderRuntimeConfig* config) override;
+  ~BitrateController() override;
+
+  void UpdateNetworkMetrics(const NetworkMetrics& network_metrics) override;
+
+  void MakeDecision(AudioNetworkAdaptor::EncoderRuntimeConfig* config) override;
 
  private:
   const Config config_;
   int bitrate_bps_;
   int frame_length_ms_;
+  rtc::Optional<int> target_audio_bitrate_bps_;
+  rtc::Optional<size_t> overhead_bytes_per_packet_;
   RTC_DISALLOW_COPY_AND_ASSIGN(BitrateController);
 };