Revert of Make the new jitter buffer the default jitter buffer.

webrtc/modules/video_coding/frame_buffer2.h

Index: webrtc/modules/video_coding/frame_buffer2.h
diff --git a/webrtc/modules/video_coding/frame_buffer2.h b/webrtc/modules/video_coding/frame_buffer2.h
index d954bf28a9d1dd326924ecfcfb72c71105b1c9af..b41ef2ff340e546517d48c2b12b65649561d9dc3 100644
--- a/webrtc/modules/video_coding/frame_buffer2.h
+++ b/webrtc/modules/video_coding/frame_buffer2.h
@@ -28,7 +28,6 @@
 namespace webrtc {
 
 class Clock;
-class VCMReceiveStatisticsCallback;
 class VCMJitterEstimator;
 class VCMTiming;
 
@@ -40,8 +39,7 @@
 
   FrameBuffer(Clock* clock,
               VCMJitterEstimator* jitter_estimator,
-              VCMTiming* timing,
-              VCMReceiveStatisticsCallback* stats_proxy);
+              VCMTiming* timing);
 
   virtual ~FrameBuffer();
 
@@ -143,6 +141,8 @@
 
   void UpdateJitterDelay() EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
+  void UpdateHistograms() const;
+
   FrameMap frames_ GUARDED_BY(crit_);
 
   rtc::CriticalSection crit_;
@@ -157,9 +157,16 @@
   int num_frames_buffered_ GUARDED_BY(crit_);
   bool stopped_ GUARDED_BY(crit_);
   VCMVideoProtection protection_mode_ GUARDED_BY(crit_);
-  VCMReceiveStatisticsCallback* const stats_callback_;
 
   RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(FrameBuffer);
+
+  // For WebRTC.Video.JitterBufferDelayInMs metric.
+  int64_t accumulated_delay_ = 0;
+  int64_t accumulated_delay_samples_ = 0;
+
+  // For WebRTC.Video.KeyFramesReceivedInPermille metric.
+  int64_t num_total_frames_ = 0;
+  int64_t num_key_frames_ = 0;
 };
 
 }  // namespace video_coding