Wire up RTP keep-alive in ortc api.

webrtc/call/rtp_transport_controller_send.h

 /*
  *  Copyright (c) 2017 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_CALL_RTP_TRANSPORT_CONTROLLER_SEND_H_
 #define WEBRTC_CALL_RTP_TRANSPORT_CONTROLLER_SEND_H_
 
 #include "webrtc/call/rtp_transport_controller_send_interface.h"
+#include "webrtc/common_types.h"
 #include "webrtc/modules/congestion_controller/include/send_side_congestion_controller.h"
 #include "webrtc/rtc_base/constructormagic.h"
 
 namespace webrtc {
 class Clock;
 class RtcEventLog;
 
 // TODO(nisse): When we get the underlying transports here, we should
 // have one object implementing RtpTransportControllerSendInterface
 // per transport, sharing the same congestion controller.
 class RtpTransportControllerSend : public RtpTransportControllerSendInterface {
  public:
   RtpTransportControllerSend(Clock* clock, webrtc::RtcEventLog* event_log);
 
   // Implements RtpTransportControllerSendInterface
   PacketRouter* packet_router() override;
   SendSideCongestionController* send_side_cc() override;
   TransportFeedbackObserver* transport_feedback_observer() override;
   RtpPacketSender* packet_sender() override;
+  const RtpKeepAliveConfig& keepalive_config() const override;
+
+  void SetKeepAliveConfig(const RtpKeepAliveConfig& config);
 
  private:
   PacketRouter packet_router_;
   SendSideCongestionController send_side_cc_;
+  RtpKeepAliveConfig keepalive_;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(RtpTransportControllerSend);
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_CALL_RTP_TRANSPORT_CONTROLLER_SEND_H_