Bug 1653626: Lock here to prevent races. r=dminor

Differential Revision: https://phabricator.services.mozilla.com/D85295

media/webrtc/trunk/webrtc/modules/rtp_rtcp/source/rtcp_receiver.cc

@@ -259,6 +259,7 @@ bool RTCPReceiver::NTP(uint32_t* received_ntp_secs,
 void RTCPReceiver::RemoteRTCPSenderInfo(uint32_t* packet_count,
                                         uint32_t* octet_count,
                                         NtpTime* ntp_timestamp) const {
+  rtc::CritScope lock(&rtcp_receiver_lock_);
   *packet_count = remote_sender_packet_count_;
   *octet_count = remote_sender_octet_count_;
   *ntp_timestamp = remote_sender_ntp_time_;