Revert of Fix the video buffer size should take rtt into consideration

webrtc/video/video_receive_stream.h

Index: webrtc/video/video_receive_stream.h
diff --git a/webrtc/video/video_receive_stream.h b/webrtc/video/video_receive_stream.h
index dddb5f0568e1beb077fd3d2b59eef2dac3c625fe..bd70d1e5bf736b2fc408fcf54e0bec4161435549 100644
--- a/webrtc/video/video_receive_stream.h
+++ b/webrtc/video/video_receive_stream.h
@@ -49,8 +49,7 @@ class VideoReceiveStream : public webrtc::VideoReceiveStream,
                            public NackSender,
                            public KeyFrameRequestSender,
                            public video_coding::OnCompleteFrameCallback,
-                           public Syncable,
-                           public CallStatsObserver {
+                           public Syncable {
  public:
   VideoReceiveStream(RtpStreamReceiverControllerInterface* receiver_controller,
                      int num_cpu_cores,
@@ -105,9 +104,6 @@ class VideoReceiveStream : public webrtc::VideoReceiveStream,
   void OnCompleteFrame(
       std::unique_ptr<video_coding::FrameObject> frame) override;
 
-  // Implements CallStatsObserver::OnRttUpdate
-  void OnRttUpdate(int64_t avg_rtt_ms, int64_t max_rtt_ms) override;
-
   // Implements Syncable.
   int id() const override;
   rtc::Optional<Syncable::Info> GetInfo() const override;