Wire up RTP keep-alive in ortc api.

webrtc/call/rtp_transport_controller_send_interface.h

Index: webrtc/call/rtp_transport_controller_send_interface.h
diff --git a/webrtc/call/rtp_transport_controller_send_interface.h b/webrtc/call/rtp_transport_controller_send_interface.h
index 9d26e98dc2dfafef5ccf3549d03804f903ab46f8..bd71da02e948db6aea77e5b9d75d924a9784846d 100644
--- a/webrtc/call/rtp_transport_controller_send_interface.h
+++ b/webrtc/call/rtp_transport_controller_send_interface.h
@@ -15,6 +15,7 @@ namespace webrtc {
 
 class PacketRouter;
 class RtpPacketSender;
+struct RtpKeepAliveConfig;
 class SendSideCongestionController;
 class TransportFeedbackObserver;
 
@@ -50,6 +51,7 @@ class RtpTransportControllerSendInterface {
   virtual TransportFeedbackObserver* transport_feedback_observer() = 0;
 
   virtual RtpPacketSender* packet_sender() = 0;
+  virtual const RtpKeepAliveConfig& keepalive_config() const = 0;
 };
 
 }  // namespace webrtc