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

webrtc/modules/video_coding/frame_buffer2.cc

Index: webrtc/modules/video_coding/frame_buffer2.cc
diff --git a/webrtc/modules/video_coding/frame_buffer2.cc b/webrtc/modules/video_coding/frame_buffer2.cc
index 016a24e80776f3a3950abfa88e6271ff6b6d8b10..a783657f3ef7cb7bda69211da1cc2224a453e1d3 100644
--- a/webrtc/modules/video_coding/frame_buffer2.cc
+++ b/webrtc/modules/video_coding/frame_buffer2.cc
@@ -147,8 +147,6 @@ FrameBuffer::ReturnReason FrameBuffer::NextFrame(
         float rtt_mult = protection_mode_ == kProtectionNackFEC ? 0.0 : 1.0;
         timing_->SetJitterDelay(jitter_estimator_->GetJitterEstimate(rtt_mult));
         timing_->UpdateCurrentDelay(frame->RenderTime(), now_ms);
-      } else {
-        jitter_estimator_->FrameNacked();
       }
 
       // Gracefully handle bad RTP timestamps and render time issues.
@@ -249,11 +247,6 @@ void FrameBuffer::Stop() {
   new_continuous_frame_event_.Set();
 }
 
-void FrameBuffer::UpdateRtt(int64_t rtt_ms) {
-  rtc::CritScope lock(&crit_);
-  jitter_estimator_->UpdateRtt(rtt_ms);
-}
-
 bool FrameBuffer::ValidReferences(const FrameObject& frame) const {
   for (size_t i = 0; i < frame.num_references; ++i) {
     if (AheadOrAt(frame.references[i], frame.picture_id))