Wire up FlexfecSender in RTPSender and add unit tests.

webrtc/modules/rtp_rtcp/include/rtp_rtcp.h

 /*
  *  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.
  */
 
 #ifndef WEBRTC_MODULES_RTP_RTCP_INCLUDE_RTP_RTCP_H_
 #define WEBRTC_MODULES_RTP_RTCP_INCLUDE_RTP_RTCP_H_
 
 #include <set>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "webrtc/base/constructormagic.h"
 #include "webrtc/base/deprecation.h"
 #include "webrtc/modules/include/module.h"
+#include "webrtc/modules/rtp_rtcp/include/flexfec_sender.h"
 #include "webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h"
 #include "webrtc/modules/video_coding/include/video_coding_defines.h"
 
 namespace webrtc {
 
 // Forward declarations.
 class RateLimiter;
 class ReceiveStatistics;
 class RemoteBitrateEstimator;
 class RtcEventLog;
@@ skipping 36 matching lines @@
     RtcpRttStats* rtt_stats = nullptr;
     RtcpPacketTypeCounterObserver* rtcp_packet_type_counter_observer = nullptr;
 
     // Estimates the bandwidth available for a set of streams from the same
     // client.
     RemoteBitrateEstimator* remote_bitrate_estimator = nullptr;
 
     // Spread any bursts of packets into smaller bursts to minimize packet loss.
     RtpPacketSender* paced_sender = nullptr;
 
+    // Generate FlexFEC packets.
+    // TODO(brandtr): Remove when FlexfecSender is wired up to PacedSender.
+    FlexfecSender* flexfec_sender = nullptr;
+
     TransportSequenceNumberAllocator* transport_sequence_number_allocator =
         nullptr;
     BitrateStatisticsObserver* send_bitrate_observer = nullptr;
     FrameCountObserver* send_frame_count_observer = nullptr;
     SendSideDelayObserver* send_side_delay_observer = nullptr;
     RtcEventLog* event_log = nullptr;
     SendPacketObserver* send_packet_observer = nullptr;
     RateLimiter* retransmission_rate_limiter = nullptr;
 
    private:
@@ skipping 374 matching lines @@
   virtual int32_t SetKeyFrameRequestMethod(KeyFrameRequestMethod method) = 0;
 
   // Sends a request for a keyframe.
   // Returns -1 on failure else 0.
   virtual int32_t RequestKeyFrame() = 0;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_RTP_RTCP_INCLUDE_RTP_RTCP_H_