Adding fraction of filter divergence in AEC metrics.

webrtc/modules/audio_processing/aec/aec_core_internal.h

Index: webrtc/modules/audio_processing/aec/aec_core_internal.h
diff --git a/webrtc/modules/audio_processing/aec/aec_core_internal.h b/webrtc/modules/audio_processing/aec/aec_core_internal.h
index 810d517834fe07d31793d8dfb89cc686a64ef4bf..c43811aa953875f5beebe4aca533bcbb0b1e655e 100644
--- a/webrtc/modules/audio_processing/aec/aec_core_internal.h
+++ b/webrtc/modules/audio_processing/aec/aec_core_internal.h
@@ -11,12 +11,15 @@
 #ifndef WEBRTC_MODULES_AUDIO_PROCESSING_AEC_AEC_CORE_INTERNAL_H_
 #define WEBRTC_MODULES_AUDIO_PROCESSING_AEC_AEC_CORE_INTERNAL_H_
 
+#include <memory>
+
 extern "C" {
 #include "webrtc/common_audio/ring_buffer.h"
 }
 #include "webrtc/common_audio/wav_file.h"
 #include "webrtc/modules/audio_processing/aec/aec_common.h"
 #include "webrtc/modules/audio_processing/aec/aec_core.h"
+#include "webrtc/modules/audio_processing/utility/mean_calculator.h"
 #include "webrtc/typedefs.h"
 
 namespace webrtc {
@@ -120,6 +123,7 @@ struct AecCore {
   Stats erle;
   Stats aNlp;
   Stats rerl;
+  std::unique_ptr<webrtc::MeanCalculator> fraction_filter_divergent;
 
   // Quantities to control H band scaling for SWB input
   int freq_avg_ic;       // initial bin for averaging nlp gain