Add log message to help analyze why echo likelihood > 1.1

webrtc/modules/audio_processing/echo_detector/normalized_covariance_estimator.h

Index: webrtc/modules/audio_processing/echo_detector/normalized_covariance_estimator.h
diff --git a/webrtc/modules/audio_processing/echo_detector/normalized_covariance_estimator.h b/webrtc/modules/audio_processing/echo_detector/normalized_covariance_estimator.h
index f77a30ec73c25183112ed26bc34d6945fecda43b..da5ff34f2fbc50a810b898985df6929264c26fb3 100644
--- a/webrtc/modules/audio_processing/echo_detector/normalized_covariance_estimator.h
+++ b/webrtc/modules/audio_processing/echo_detector/normalized_covariance_estimator.h
@@ -28,6 +28,7 @@ class NormalizedCovarianceEstimator {
   float normalized_cross_correlation() const {
     return normalized_cross_correlation_;
   }
+  float covariance() const { return covariance_; }
   // This function resets the estimated values to zero.
   void Clear();