Return false if PeerConnection::GetStats() is called on invalid tracks

webrtc/api/peerconnection.cc

 /*
  *  Copyright 2012 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 868 matching lines @@
                               MediaStreamTrackInterface* track,
                               StatsOutputLevel level) {
   TRACE_EVENT0("webrtc", "PeerConnection::GetStats");
   RTC_DCHECK(signaling_thread()->IsCurrent());
   if (!VERIFY(observer != NULL)) {
     LOG(LS_ERROR) << "GetStats - observer is NULL.";
     return false;
   }
 
   stats_->UpdateStats(level);
+  // The StatsCollector is used to tell if a track is valid because it may
+  // remember tracks that the PeerConnection previously removed.
+  if (track && !stats_->IsValidTrack(track->id())) {
+    LOG(LS_WARNING) << "GetStats is called with an invalid track: "
+                    << track->id();
+    return false;
+  }
   signaling_thread()->Post(RTC_FROM_HERE, this, MSG_GETSTATS,
                            new GetStatsMsg(observer, track));
   return true;
 }
 
 void PeerConnection::GetStats(RTCStatsCollectorCallback* callback) {
   RTC_DCHECK(stats_collector_);
   stats_collector_->GetStatsReport(callback);
 }
 
@@ skipping 1443 matching lines @@
 
 bool PeerConnection::StartRtcEventLog_w(rtc::PlatformFile file,
                                         int64_t max_size_bytes) {
   return event_log_->StartLogging(file, max_size_bytes);
 }
 
 void PeerConnection::StopRtcEventLog_w() {
   event_log_->StopLogging();
 }
 }  // namespace webrtc