Wire up FlexfecSender in RTPSender and add unit tests.

webrtc/modules/rtp_rtcp/source/rtp_sender_video.cc

 /*
  *  Copyright (c) 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 26 matching lines @@
                      RtpPacketToSend* red_packet) {
   uint8_t* red_payload = red_packet->AllocatePayload(
       kRedForFecHeaderLength + media_packet.payload_size());
   RTC_DCHECK(red_payload);
   red_payload[0] = media_packet.PayloadType();
   memcpy(&red_payload[kRedForFecHeaderLength], media_packet.payload(),
          media_packet.payload_size());
 }
 }  // namespace
 
-RTPSenderVideo::RTPSenderVideo(Clock* clock, RTPSender* rtp_sender)
+RTPSenderVideo::RTPSenderVideo(Clock* clock,
+                               RTPSender* rtp_sender,
+                               FlexfecSender* flexfec_sender)
     : rtp_sender_(rtp_sender),
       clock_(clock),
       video_type_(kRtpVideoGeneric),
       retransmission_settings_(kRetransmitBaseLayer),
       last_rotation_(kVideoRotation_0),
       red_payload_type_(-1),
       ulpfec_payload_type_(-1),
-      flexfec_sender_(nullptr),  // TODO(brandtr): Wire up in future CL.
+      flexfec_sender_(flexfec_sender),
       delta_fec_params_{0, 1, kFecMaskRandom},
       key_fec_params_{0, 1, kFecMaskRandom},
       fec_bitrate_(1000, RateStatistics::kBpsScale),
       video_bitrate_(1000, RateStatistics::kBpsScale) {
   encoder_checker_.Detach();
 }
 
 RTPSenderVideo::~RTPSenderVideo() {}
 
 void RTPSenderVideo::SetVideoCodecType(RtpVideoCodecTypes video_type) {
@@ skipping 345 matching lines @@
   rtc::CritScope cs(&crit_);
   return retransmission_settings_;
 }
 
 void RTPSenderVideo::SetSelectiveRetransmissions(uint8_t settings) {
   rtc::CritScope cs(&crit_);
   retransmission_settings_ = settings;
 }
 
 }  // namespace webrtc