Add new ANA stats to GetStats() to count the number of actions taken by each controller.

webrtc/api/audio_codecs/audio_encoder.h

Index: webrtc/api/audio_codecs/audio_encoder.h
diff --git a/webrtc/api/audio_codecs/audio_encoder.h b/webrtc/api/audio_codecs/audio_encoder.h
index bd8c7deb942ab9bf9006c3845c7bd9d996291c4b..60e0a0705d0253d7c4f06a556443ca51e3475165 100644
--- a/webrtc/api/audio_codecs/audio_encoder.h
+++ b/webrtc/api/audio_codecs/audio_encoder.h
@@ -16,6 +16,7 @@
 #include <string>
 #include <vector>
 
+#include "webrtc/common_types.h"
 #include "webrtc/rtc_base/array_view.h"
 #include "webrtc/rtc_base/buffer.h"
 #include "webrtc/rtc_base/deprecation.h"
@@ -203,6 +204,9 @@ class AudioEncoder {
   virtual void SetReceiverFrameLengthRange(int min_frame_length_ms,
                                            int max_frame_length_ms);
 
+  // Get statistics related to audio network adaptation.
+  virtual ANAStats GetANAStats() const;
+
  protected:
   // Subclasses implement this to perform the actual encoding. Called by
   // Encode().