Update the BWE when the network route changes.

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 5767448a5f7bf711a24ef214ea47d5f5cac18f20..de36031e9da348aac434732925618aff7324b04c 100644
--- a/webrtc/modules/congestion_controller/congestion_controller.cc
+++ b/webrtc/modules/congestion_controller/congestion_controller.cc
@@ -212,21 +212,25 @@ void CongestionController::Init() {
       min_bitrate_bps_);
 }
 
-
-void CongestionController::SetBweBitrates(int min_bitrate_bps,
-                                          int start_bitrate_bps,
-                                          int max_bitrate_bps) {
+void CongestionController::ClampBitrates(int* bitrate_bps,

[stefan-webrtc, 2016/05/30 06:47:03]

Seems like this can be a static function within this file only as it doesn't
access any members of the class. Move it to the top of the file too.

[honghaiz3, 2016/05/31 16:58:03]

Done.

+                                         int* min_bitrate_bps,
+                                         int* max_bitrate_bps) {
   // TODO(holmer): We should make sure the default bitrates are set to 10 kbps,
   // and that we don't try to set the min bitrate to 0 from any applications.
   // The congestion controller should allow a min bitrate of 0.
   const int kMinBitrateBps = 10000;
-  if (min_bitrate_bps < kMinBitrateBps)
-    min_bitrate_bps = kMinBitrateBps;
-  if (max_bitrate_bps > 0)
-    max_bitrate_bps = std::max(min_bitrate_bps, max_bitrate_bps);
-  if (start_bitrate_bps > 0)
-    start_bitrate_bps = std::max(min_bitrate_bps, start_bitrate_bps);
+  if (*min_bitrate_bps < kMinBitrateBps)
+    *min_bitrate_bps = kMinBitrateBps;
+  if (*max_bitrate_bps > 0)
+    *max_bitrate_bps = std::max(*min_bitrate_bps, *max_bitrate_bps);
+  if (*bitrate_bps > 0)
+    *bitrate_bps = std::max(*min_bitrate_bps, *bitrate_bps);
+}
 
+void CongestionController::SetBweBitrates(int min_bitrate_bps,
+                                          int start_bitrate_bps,
+                                          int max_bitrate_bps) {
+  ClampBitrates(&start_bitrate_bps, &min_bitrate_bps, &max_bitrate_bps);
   bitrate_controller_->SetBitrates(start_bitrate_bps,
                                    min_bitrate_bps,
                                    max_bitrate_bps);
@@ -239,6 +243,25 @@ void CongestionController::SetBweBitrates(int min_bitrate_bps,
   MaybeTriggerOnNetworkChanged();
 }
 
+void CongestionController::ResetBweBitrates(int bitrate_bps,

[stefan-webrtc, 2016/05/30 06:47:03]

ResetBitrates() or maybe ResetBwe() to make it clear that not only bitrates are
reset, also the BWE state.

[honghaiz3, 2016/05/31 16:58:03]

Based on your comments, will it be clearer to use ResetBweAndBitrates?

[stefan-webrtc, 2016/05/31 17:27:49]

That works

+                                            int min_bitrate_bps,
+                                            int max_bitrate_bps) {
+  ClampBitrates(&bitrate_bps, &min_bitrate_bps, &max_bitrate_bps);
+  bitrate_controller_->ResetBitrates(bitrate_bps, min_bitrate_bps,
+                                     max_bitrate_bps);
+  min_bitrate_bps_ = min_bitrate_bps;
+  if (remote_bitrate_estimator_) {

[stefan-webrtc, 2016/05/30 06:47:03]

Remove {}

[honghaiz3, 2016/05/31 16:58:03]

Done.

+    remote_bitrate_estimator_->SetMinBitrate(min_bitrate_bps);
+  }
+
+  RemoteBitrateEstimator* rbe =
+      new RemoteBitrateEstimatorAbsSendTime(&transport_feedback_adapter_);
+  transport_feedback_adapter_.SetBitrateEstimator(rbe);

[stefan-webrtc, 2016/05/30 06:47:03]

Will the previous rbe be deleted?

[honghaiz3, 2016/05/31 16:58:03]

Yes, the bitrate_estimator_ is a unique_ptr. 

+  rbe->SetMinBitrate(min_bitrate_bps);
+

[stefan-webrtc, 2016/05/30 06:47:03]

Could you add a TODO which says "TODO(holmer): Trigger a new probe once mid-call
probing is implemented."? 

[honghaiz3, 2016/05/31 16:58:03]

Done.

+  MaybeTriggerOnNetworkChanged();
+}
+
 BitrateController* CongestionController::GetBitrateController() const {
   return bitrate_controller_.get();
 }