Add a FlexfecReceiver class.

webrtc/modules/BUILD.gn

 # 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.
 
 import("../build/webrtc.gni")
 import("audio_coding/audio_coding.gni")
@@ skipping 387 matching lines @@
       "remote_bitrate_estimator/send_time_history_unittest.cc",
       "remote_bitrate_estimator/test/bwe_test_framework_unittest.cc",
       "remote_bitrate_estimator/test/bwe_unittest.cc",
       "remote_bitrate_estimator/test/estimators/nada_unittest.cc",
       "remote_bitrate_estimator/test/metric_recorder_unittest.cc",
       "rtp_rtcp/source/byte_io_unittest.cc",
       "rtp_rtcp/source/fec_receiver_unittest.cc",
       "rtp_rtcp/source/fec_test_helper.cc",
       "rtp_rtcp/source/fec_test_helper.h",
       "rtp_rtcp/source/flexfec_header_reader_writer_unittest.cc",
+      "rtp_rtcp/source/flexfec_receiver_unittest.cc",
       "rtp_rtcp/source/mock/mock_rtp_payload_strategy.h",
       "rtp_rtcp/source/nack_rtx_unittest.cc",
       "rtp_rtcp/source/packet_loss_stats_unittest.cc",
       "rtp_rtcp/source/playout_delay_oracle_unittest.cc",
       "rtp_rtcp/source/producer_fec_unittest.cc",
       "rtp_rtcp/source/receive_statistics_unittest.cc",
       "rtp_rtcp/source/remote_ntp_time_estimator_unittest.cc",
       "rtp_rtcp/source/rtcp_packet/app_unittest.cc",
       "rtp_rtcp/source/rtcp_packet/bye_unittest.cc",
       "rtp_rtcp/source/rtcp_packet/common_header_unittest.cc",
@@ skipping 281 matching lines @@
       ]
 
       if (target_cpu != "x64") {
         sources += [ "audio_device/ios/audio_device_unittest_ios.cc" ]
       }
 
       ldflags = [ "-ObjC" ]
     }
   }
 }