Implement periodic bandwidth probing in application-limited region.

webrtc/modules/congestion_controller/congestion_controller.cc

Index: webrtc/modules/congestion_controller/congestion_controller.cc
diff --git a/webrtc/modules/congestion_controller/congestion_controller.cc b/webrtc/modules/congestion_controller/congestion_controller.cc
index accc1411f995487895f1ba35bb1851538c83948b..b1195f89fc71b44bad7a529720cee46d91fa2767 100644
--- a/webrtc/modules/congestion_controller/congestion_controller.cc
+++ b/webrtc/modules/congestion_controller/congestion_controller.cc
@@ -275,6 +275,10 @@ RateLimiter* CongestionController::GetRetransmissionRateLimiter() {
   return retransmission_rate_limiter_.get();
 }
 
+void CongestionController::EnablePeriodicProbing(bool enable) {
+  probe_controller_->EnablePeriodicProbing(enable);
+}
+
 void CongestionController::SetAllocatedSendBitrateLimits(
     int min_send_bitrate_bps,
     int max_padding_bitrate_bps) {
@@ -319,6 +323,7 @@ int64_t CongestionController::TimeUntilNextProcess() {
 void CongestionController::Process() {
   bitrate_controller_->Process();
   remote_bitrate_estimator_->Process();
+  probe_controller_->Process();
   MaybeTriggerOnNetworkChanged();
 }