CongestionController::SetBweBitrates may now trigger probing.

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 88bc9071364ea8f169f957cc9e9d38aa35f3f59e..3ef4c993f44032a7abf7b159deda37da93815b49 100644
--- a/webrtc/modules/congestion_controller/congestion_controller.cc
+++ b/webrtc/modules/congestion_controller/congestion_controller.cc
@@ -171,6 +171,7 @@ CongestionController::CongestionController(
       remote_estimator_proxy_(clock_, packet_router_.get()),
       transport_feedback_adapter_(bitrate_controller_.get(), clock_),
       min_bitrate_bps_(RemoteBitrateEstimator::kDefaultMinBitrateBps),
+      max_bitrate_bps_(0),
       last_reported_bitrate_bps_(0),
       last_reported_fraction_loss_(0),
       last_reported_rtt_(0),
@@ -200,6 +201,7 @@ CongestionController::CongestionController(
       remote_estimator_proxy_(clock_, packet_router_.get()),
       transport_feedback_adapter_(bitrate_controller_.get(), clock_),
       min_bitrate_bps_(RemoteBitrateEstimator::kDefaultMinBitrateBps),
+      max_bitrate_bps_(0),
       last_reported_bitrate_bps_(0),
       last_reported_fraction_loss_(0),
       last_reported_rtt_(0),
@@ -224,6 +226,16 @@ void CongestionController::SetBweBitrates(int min_bitrate_bps,
                                    min_bitrate_bps,
                                    max_bitrate_bps);
 
+  {
+    rtc::CritScope cs(&critsect_);
+    if (last_reported_bitrate_bps_ != 0 &&

[stefan-webrtc, 2016/08/16 11:48:39]

Add comment to explain why we don't do this if no bitrate has been reported and
why the max bitrate must have been increased.

[philipel, 2016/08/16 13:04:31]

Done.

+        last_reported_bitrate_bps_ < static_cast<uint32_t>(max_bitrate_bps) &&
+        max_bitrate_bps_ < max_bitrate_bps) {

[stefan-webrtc, 2016/08/16 11:48:39]

I think it's easier to read if we do max_bitrate_bps > max_bitrate_bps_, but
maybe I'm just odd. :)

[philipel, 2016/08/16 13:04:31]

Done.

+      pacer_->ProbeAtBitrate(max_bitrate_bps, 5);
+    }
+  }
+  max_bitrate_bps_ = max_bitrate_bps;
+
   if (remote_bitrate_estimator_)
     remote_bitrate_estimator_->SetMinBitrate(min_bitrate_bps);
   min_bitrate_bps_ = min_bitrate_bps;
@@ -241,6 +253,7 @@ void CongestionController::ResetBweAndBitrates(int bitrate_bps,
   bitrate_controller_->ResetBitrates(bitrate_bps, min_bitrate_bps,
                                      max_bitrate_bps);
   min_bitrate_bps_ = min_bitrate_bps;
+  max_bitrate_bps_ = max_bitrate_bps;
   // TODO(honghaiz): Recreate this object once the remote bitrate estimator is
   // no longer exposed outside CongestionController.
   if (remote_bitrate_estimator_)