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

webrtc/common_types.h

Index: webrtc/common_types.h
diff --git a/webrtc/common_types.h b/webrtc/common_types.h
index ac5c2e2e7b5aeaf7673a2b790c5cb0fd9ff69268..59f8ad043a8c6b86a2656bc334df9908b4a4bfd1 100644
--- a/webrtc/common_types.h
+++ b/webrtc/common_types.h
@@ -433,6 +433,28 @@ struct AudioDecodingCallStats {
   int decoded_muted_output;  // Number of calls returning a muted state output.
 };
 
+// Statistics related to Audio Network Adaptation.
+struct ANAStats {
+  ANAStats();
+  ANAStats(const ANAStats&);
+  ~ANAStats();
+  // Number of actions taken by the ANA bitrate controller since the start of

[ossu, 2017/09/05 10:19:02]

Please also include an explanation for what an empty value means in these
comments.

[ivoc, 2017/09/06 11:46:16]

Done!

+  // the call.
+  rtc::Optional<uint32_t> bitrate_action_counter;
+  // Number of actions taken by the ANA channel controller since the start of
+  // the call.
+  rtc::Optional<uint32_t> channel_action_counter;
+  // Number of actions taken by the ANA DTX controller since the start of the
+  // call.
+  rtc::Optional<uint32_t> dtx_action_counter;
+  // Number of actions taken by the ANA FEC controller since the start of the
+  // call.
+  rtc::Optional<uint32_t> fec_action_counter;
+  // Number of actions taken by the ANA frame length controller since the start
+  // of the call.
+  rtc::Optional<uint32_t> frame_length_action_counter;
+};
+
 // ==================================================================
 // Video specific types
 // ==================================================================