Disables congestion window in pacer when CongestionWindowPushback is enabled.

Bug: None
Change-Id: I21a26fd6e32eadf1f2a619f6f3cc72da779fa0d3
Reviewed-on: https://webrtc-review.googlesource.com/83727
Commit-Queue: Ying Wang <yinwa@webrtc.org>
Reviewed-by: Christoffer Rodbro <crodbro@webrtc.org>
Reviewed-by: Sebastian Jansson <srte@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23627}
diff --git a/modules/congestion_controller/rtp/send_side_congestion_controller.cc b/modules/congestion_controller/rtp/send_side_congestion_controller.cc
index a75c1bc..ace522c 100644
--- a/modules/congestion_controller/rtp/send_side_congestion_controller.cc
+++ b/modules/congestion_controller/rtp/send_side_congestion_controller.cc
@@ -236,7 +236,9 @@
   RTC_DCHECK_CALLED_SEQUENTIALLY(&sequenced_checker_);
   if (update.congestion_window) {
     congestion_window_ = update.congestion_window;
-    pacer_controller_->OnCongestionWindow(*update.congestion_window);
+    if (!congestion_window_pushback_experiment_) {
+      pacer_controller_->OnCongestionWindow(*update.congestion_window);
+    }
   }
   if (update.pacer_config) {
     pacer_controller_->OnPacerConfig(*update.pacer_config);