Wire up RTP keep-alive in ortc api.

webrtc/call/rtp_transport_controller_send.cc

Index: webrtc/call/rtp_transport_controller_send.cc
diff --git a/webrtc/call/rtp_transport_controller_send.cc b/webrtc/call/rtp_transport_controller_send.cc
index 878aa191a37332c3bde8bf697bfa841d3566ad52..b8b65a0d554dfbcba8fc48c37cb62536bf7b6c1f 100644
--- a/webrtc/call/rtp_transport_controller_send.cc
+++ b/webrtc/call/rtp_transport_controller_send.cc
@@ -35,4 +35,13 @@ RtpPacketSender* RtpTransportControllerSend::packet_sender() {
   return send_side_cc_.pacer();
 }
 
+const RtpKeepAliveConfig& RtpTransportControllerSend::keepalive_config() const {
+  return keepalive_;
+}
+
+void RtpTransportControllerSend::SetKeepAliveConfig(
+    const RtpKeepAliveConfig& config) {
+  keepalive_ = config;
+}
+
 }  // namespace webrtc