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

webrtc/modules/audio_coding/acm2/audio_coding_module.cc

Index: webrtc/modules/audio_coding/acm2/audio_coding_module.cc
diff --git a/webrtc/modules/audio_coding/acm2/audio_coding_module.cc b/webrtc/modules/audio_coding/acm2/audio_coding_module.cc
index 14958181859501459181f56380e79bf885e40376..ac5c4cd34c2f01520869ca94bb9663cc5156534b 100644
--- a/webrtc/modules/audio_coding/acm2/audio_coding_module.cc
+++ b/webrtc/modules/audio_coding/acm2/audio_coding_module.cc
@@ -204,6 +204,8 @@ class AudioCodingModuleImpl final : public AudioCodingModule {
 
   void GetDecodingCallStatistics(AudioDecodingCallStats* stats) const override;
 
+  AudioEncoder::AudioEncoderStats GetAudioEncoderStatistics() const override;
+
  private:
   struct InputData {
     uint32_t input_timestamp;
@@ -1270,6 +1272,15 @@ void AudioCodingModuleImpl::GetDecodingCallStatistics(
   receiver_.GetDecodingCallStatistics(call_stats);
 }
 
+AudioEncoder::AudioEncoderStats
+AudioCodingModuleImpl::GetAudioEncoderStatistics() const {
+  rtc::CritScope lock(&acm_crit_sect_);
+  if (encoder_stack_)
+    return encoder_stack_->GetStats();
+  // If no encoder is set, return default stats.
+  return AudioEncoder::AudioEncoderStats();
+}
+
 }  // namespace
 
 AudioCodingModule::Config::Config()