Remove old WebRTC-NewVideoJitterBuffer used for testing the NackModule.

This experiment was used to test the NackModule but will soon (tm) be used to
test the completly new video jitter buffer.

BUG=webrtc:5514
R=stefan@webrtc.org

Review URL: https://codereview.webrtc.org/2123913002 .

Cr-Commit-Position: refs/heads/master@{#13395}
diff --git a/webrtc/modules/video_coding/jitter_buffer.cc b/webrtc/modules/video_coding/jitter_buffer.cc
index ff37e21..7cd874c 100644
--- a/webrtc/modules/video_coding/jitter_buffer.cc
+++ b/webrtc/modules/video_coding/jitter_buffer.cc
@@ -215,20 +215,6 @@
   }
 }
 
-static NackModule*
-MaybeCreateNackModule(Clock* clock,
-                      NackSender* nack_sender,
-                      KeyFrameRequestSender* keyframe_request_sender) {
-if (field_trial::FindFullName("WebRTC-NewVideoJitterBuffer") == "Enabled") {
-    // Only create a nack module if a nack sender is available.
-    if (nack_sender) {
-      RTC_DCHECK(keyframe_request_sender);
-      return new NackModule(clock, nack_sender, keyframe_request_sender);
-    }
-  }
-  return nullptr;
-}
-
 VCMJitterBuffer::VCMJitterBuffer(Clock* clock,
                                  std::unique_ptr<EventWrapper> event,
                                  NackSender* nack_sender,
@@ -266,10 +252,7 @@
       max_incomplete_time_ms_(0),
       decode_error_mode_(kNoErrors),
       average_packets_per_frame_(0.0f),
-      frame_counter_(0),
-      nack_module_(MaybeCreateNackModule(clock,
-                                         nack_sender,
-                                         keyframe_request_sender)) {
+      frame_counter_(0) {
   for (int i = 0; i < kStartNumberOfFrames; i++)
     free_frames_.push_back(new VCMFrameBuffer());
 }
@@ -349,8 +332,6 @@
   UpdateHistograms();
   running_ = false;
   last_decoded_state_.Reset();
-  if (nack_module_)
-    nack_module_->Stop();
 
   // Make sure all frames are free and reset.
   for (FrameList::iterator it = decodable_frames_.begin();
@@ -391,8 +372,6 @@
   waiting_for_completion_.latest_packet_time = -1;
   first_packet_since_reset_ = true;
   missing_sequence_numbers_.clear();
-  if (nack_module_)
-    nack_module_->Clear();
 }
 
 // Get received key and delta frames
@@ -609,8 +588,6 @@
   if ((*frame).IsSessionComplete())
     UpdateAveragePacketsPerFrame(frame->NumPackets());
 
-  if (nack_module_)
-    nack_module_->ClearUpTo(frame->GetHighSeqNum());
   return frame;
 }
 
@@ -671,9 +648,6 @@
                                                  bool* retransmitted) {
   CriticalSectionScoped cs(crit_sect_);
 
-  if (nack_module_)
-    nack_module_->OnReceivedPacket(packet);
-
   ++num_packets_;
   if (num_packets_ == 1) {
     time_first_packet_ms_ = clock_->TimeInMilliseconds();
@@ -936,8 +910,6 @@
   CriticalSectionScoped cs(crit_sect_);
   rtt_ms_ = rtt_ms;
   jitter_estimate_.UpdateRtt(rtt_ms);
-  if (nack_module_)
-    nack_module_->UpdateRtt(rtt_ms);
   if (!WaitForRetransmissions())
     jitter_estimate_.ResetNackCount();
 }
@@ -1059,14 +1031,6 @@
       }
     }
   }
-  // The experiment is running, the nack module will send Nacks.
-  // The reason we allow the major part of the GetNackList function to
-  // run even if we are running the experiment is because this
-  // function is also used to signal that the jitter buffer wants to
-  // request a keyframe.
-  if (nack_module_)
-    return std::vector<uint16_t>();
-
   std::vector<uint16_t> nack_list(missing_sequence_numbers_.begin(),
                                   missing_sequence_numbers_.end());
   return nack_list;
@@ -1351,14 +1315,4 @@
   return true;
 }
 
-int64_t VCMJitterBuffer::TimeUntilNextProcess() {
-  if (nack_module_)
-    return nack_module_->TimeUntilNextProcess();
-  return std::numeric_limits<int64_t>::max();
-}
-
-void VCMJitterBuffer::Process() {
-  if (nack_module_)
-    nack_module_->Process();
-}
 }  // namespace webrtc