Fix delay plot crash in event_log_visualizer.

webrtc/tools/event_log_visualizer/analyzer.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 1086 matching lines @@
     if (kv.first.GetDirection() == PacketDirection::kIncomingPacket) {
       for (const LoggedRtcpPacket& rtcp_packet : kv.second)
         incoming_rtcp.insert(
             std::make_pair(rtcp_packet.timestamp, &rtcp_packet));
     }
   }
 
   SimulatedClock clock(0);
   NullBitrateController null_controller;
   TransportFeedbackAdapter feedback_adapter(&clock, &null_controller);
+  feedback_adapter.InitBwe();
 
   TimeSeries time_series;
   time_series.label = "Network Delay Change";
   time_series.style = LINE_DOT_GRAPH;
   int64_t estimated_base_delay_ms = std::numeric_limits<int64_t>::max();
 
   auto rtp_iterator = outgoing_rtp.begin();
   auto rtcp_iterator = incoming_rtcp.begin();
 
   auto NextRtpTime = [&]() {
@@ skipping 50 matching lines @@
     point.y -= estimated_base_delay_ms;
   // Add the data set to the plot.
   plot->series_list_.push_back(std::move(time_series));
 
   plot->SetXAxis(0, call_duration_s_, "Time (s)", kLeftMargin, kRightMargin);
   plot->SetSuggestedYAxis(0, 10, "Delay (ms)", kBottomMargin, kTopMargin);
   plot->SetTitle("Network Delay Change.");
 }
 }  // namespace plotting
 }  // namespace webrtc