Ping backup connection at a slower rate

talk/app/webrtc/webrtcsession.cc

 /*
  * libjingle
  * Copyright 2012 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
@@ skipping 1226 matching lines @@
 bool WebRtcSession::SetIceTransports(
     PeerConnectionInterface::IceTransportsType type) {
   return port_allocator()->set_candidate_filter(
         ConvertIceTransportTypeToCandidateFilter(type));
 }
 
 cricket::IceConfig WebRtcSession::ParseIceConfig(
     const PeerConnectionInterface::RTCConfiguration& config) const {
   cricket::IceConfig ice_config;
   ice_config.receiving_timeout_ms = config.ice_connection_receiving_timeout;
+  ice_config.backup_connection_ping_interval =
+      config.ice_backup_candidate_pair_ping_interval;
   ice_config.gather_continually = (config.continual_gathering_policy ==
                                    PeerConnectionInterface::GATHER_CONTINUALLY);
   return ice_config;
 }
 
 void WebRtcSession::SetIceConfig(const cricket::IceConfig& config) {
   transport_controller_->SetIceConfig(config);
 }
 
 void WebRtcSession::MaybeStartGathering() {
@@ skipping 930 matching lines @@
   }
 }
 
 void WebRtcSession::OnSentPacket_w(cricket::TransportChannel* channel,
                                    const rtc::SentPacket& sent_packet) {
   RTC_DCHECK(worker_thread()->IsCurrent());
   media_controller_->call_w()->OnSentPacket(sent_packet);
 }
 
 }  // namespace webrtc