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

modules/video_coding/frame_buffer2.cc

 /*
  *  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 129 matching lines @@
         int64_t frame_delay;
 
         if (inter_frame_delay_.CalculateDelay(frame->timestamp, &frame_delay,
                                               frame->ReceivedTime())) {
           jitter_estimator_->UpdateEstimate(frame_delay, frame->size());
         }
 
         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.
       if (HasBadRenderTiming(*frame, now_ms)) {
         jitter_estimator_->Reset();
         timing_->Reset();
         frame->SetRenderTime(timing_->RenderTimeMs(frame->timestamp, now_ms));
       }
 
       UpdateJitterDelay();
@@ skipping 80 matching lines @@
   stopped_ = false;
 }
 
 void FrameBuffer::Stop() {
   TRACE_EVENT0("webrtc", "FrameBuffer::Stop");
   rtc::CritScope lock(&crit_);
   stopped_ = true;
   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 {
   if (frame.picture_id < 0)
     return false;
 
   for (size_t i = 0; i < frame.num_references; ++i) {
     if (frame.references[i] < 0 || frame.references[i] >= frame.picture_id)
       return false;
 
     for (size_t j = i + 1; j < frame.num_references; ++j) {
       if (frame.references[i] == frame.references[j])
@@ skipping 304 matching lines @@
   frames_.clear();
   last_decoded_frame_it_ = frames_.end();
   last_continuous_frame_it_ = frames_.end();
   next_frame_it_ = frames_.end();
   num_frames_history_ = 0;
   num_frames_buffered_ = 0;
 }
 
 }  // namespace video_coding
 }  // namespace webrtc