Add UMA stats for AEC filter divergence metric.

content/renderer/media/media_stream_audio_processor_options.h

Index: content/renderer/media/media_stream_audio_processor_options.h
diff --git a/content/renderer/media/media_stream_audio_processor_options.h b/content/renderer/media/media_stream_audio_processor_options.h
index 2d5af1d4f41261f97fba8ace5a9072c6677499cc..00c3c530cb8942dec5fd93555c53ade613fecc59 100644
--- a/content/renderer/media/media_stream_audio_processor_options.h
+++ b/content/renderer/media/media_stream_audio_processor_options.h
@@ -104,13 +104,27 @@ class CONTENT_EXPORT EchoInformation {
   virtual ~EchoInformation();
 
   void UpdateAecDelayStats(webrtc::EchoCancellation* echo_cancellation);
+  void UpdateAecDivergentFilterStats(
+      webrtc::EchoCancellation* echo_cancellation);
+  void ReportAndResetAecDivergentFilterStats();
 
  private:
   // Counter to track 5 seconds of processed 10 ms chunks in order to query a
   // new metric from webrtc::EchoCancellation::GetEchoDelayMetrics().
-  int num_chunks_;
+  int chunks_for_delay_stats_;

[minyue, 2016/06/28 08:18:41]

maybe better to count in time, e.g.,

time_for_delay_stats_ms

if you still want to use a counter of chunks, maybe better to use type "size_t"

[Henrik Grunell, 2016/06/28 09:33:10]

Yes, that's better. Done.

   bool echo_frames_received_;
 
+  // Counter to track 1 second of processed 10 ms chunks in order to query a new
+  // divergent filter fraction metric from
+  // webrtc::EchoCancellation::GetMetrics().
+  int chunks_for_divergent_filter_stats_;

[minyue, 2016/06/28 08:18:41]

maybe better to count in time, e.g.,

time_for_divergent_filter_stats_ms

[Henrik Grunell, 2016/06/28 09:33:10]

Done.

+
+  // Total number of times we queried for the divergent filter fraction metric.
+  int num_divergent_filter_fraction_;
+
+  // Number of non-zero divergent filter fraction metrics.
+  int num_non_zero_divergent_filter_fraction_;
+
   DISALLOW_COPY_AND_ASSIGN(EchoInformation);
 };