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 b2e7301724d5f7dd886f300299f07bfa978a3e6d..84f7707d91c227298434db2cad3430f05f5b99ab 100644
--- a/webrtc/modules/audio_processing/aec/aec_core_internal.h
+++ b/webrtc/modules/audio_processing/aec/aec_core_internal.h
@@ -118,6 +118,9 @@ struct AecCore {
   Stats erle;
   Stats aNlp;
   Stats rerl;
+  int num_diverge_values;
+  int num_filter_diverge;

[peah-webrtc, 2016/02/29 14:05:56]

I think it would make sense to bundle these into a struct instead as they
belong, and are only usable, together. That would simplify code readability and
refactorability.

You could then also more easily name the variables. Currently I think it could
be more clear from the variable names what they store.

+  float fraction_filter_diverge;
 
   // Quantities to control H band scaling for SWB input
   int freq_avg_ic;       // initial bin for averaging nlp gain