Add UMA stats to bad call detection.

webrtc/video/quality_threshold.h

 /*
  *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 11 matching lines @@
   // Both thresholds are inclusive, i.e. measurement >= high signifies a high
   // state, while measurement <= low signifies a low state.
   QualityThreshold(int low_threshold,
                    int high_threshold,
                    float fraction,
                    int max_measurements);
 
   void AddMeasurement(int measurement);
   rtc::Optional<bool> IsHigh() const;
   rtc::Optional<double> CalculateVariance() const;
+  rtc::Optional<double> FractionHigh(int min_required_samples) const;
 
  private:
   const std::unique_ptr<int[]> buffer_;
   const int max_measurements_;
   const float fraction_;
   const int low_threshold_;
   const int high_threshold_;
   int until_full_;
   int next_index_;
   rtc::Optional<bool> is_high_;
   int sum_;
   int count_low_;
   int count_high_;
+  int num_high_states_;
+  int num_certain_states_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_VIDEO_QUALITY_THRESHOLD_H_