Update the BWE when the network route changes.

webrtc/modules/bitrate_controller/bitrate_controller_impl.cc

Index: webrtc/modules/bitrate_controller/bitrate_controller_impl.cc
diff --git a/webrtc/modules/bitrate_controller/bitrate_controller_impl.cc b/webrtc/modules/bitrate_controller/bitrate_controller_impl.cc
index 09652d84194207b9742f10e0bb67690a1dd1a27b..c99bd53218698d21982294238d4321bfec90bada 100644
--- a/webrtc/modules/bitrate_controller/bitrate_controller_impl.cc
+++ b/webrtc/modules/bitrate_controller/bitrate_controller_impl.cc
@@ -138,6 +138,18 @@ void BitrateControllerImpl::SetBitrates(int start_bitrate_bps,
   MaybeTriggerOnNetworkChanged();
 }
 
+void BitrateControllerImpl::ResetBitrates(int bitrate_bps,
+                                          int min_bitrate_bps,
+                                          int max_bitrate_bps) {
+  {
+    rtc::CritScope cs(&critsect_);
+    bandwidth_estimation_ = SendSideBandwidthEstimation();
+    bandwidth_estimation_.SetBitrates(bitrate_bps, min_bitrate_bps,
+                                      max_bitrate_bps);
+  }
+  MaybeTriggerOnNetworkChanged();
+}
+
 void BitrateControllerImpl::SetReservedBitrate(uint32_t reserved_bitrate_bps) {
   {
     rtc::CritScope cs(&critsect_);