Add GUARDED_BY's in FlexfecReceiver.

webrtc/modules/rtp_rtcp/include/flexfec_receiver.h

 /*
  *  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 39 matching lines @@
 
  private:
   bool AddReceivedPacket(const uint8_t* packet, size_t packet_length);
   bool ProcessReceivedPackets();
 
   // Config.
   const uint32_t ssrc_;
   const uint32_t protected_media_ssrc_;
 
   // Erasure code interfacing and callback.
-  std::unique_ptr<ForwardErrorCorrection> erasure_code_;
-  ForwardErrorCorrection::ReceivedPacketList received_packets_;
-  ForwardErrorCorrection::RecoveredPacketList recovered_packets_;
-  RecoveredPacketReceiver* const callback_;
+  std::unique_ptr<ForwardErrorCorrection> erasure_code_
+      GUARDED_BY(sequence_checker_);
+  ForwardErrorCorrection::ReceivedPacketList received_packets_
+      GUARDED_BY(sequence_checker_);
+  ForwardErrorCorrection::RecoveredPacketList recovered_packets_
+      GUARDED_BY(sequence_checker_);
+  RecoveredPacketReceiver* const callback_ GUARDED_BY(sequence_checker_);
 
   // Logging and stats.
   Clock* const clock_;
-  int64_t last_recovered_packet_ms_;
-  FecPacketCounter packet_counter_;
+  int64_t last_recovered_packet_ms_ GUARDED_BY(sequence_checker_);
+  FecPacketCounter packet_counter_ GUARDED_BY(sequence_checker_);
 
   rtc::SequencedTaskChecker sequence_checker_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_RTP_RTCP_INCLUDE_FLEXFEC_RECEIVER_H_