Avoid cluster set up at max bitrate at start

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 5def7154e1bacfaa05d20eea9484e405e20d779d..f2722b487a6d690fd364f452fa3ecc93d42b5042 100644
--- a/webrtc/modules/congestion_controller/congestion_controller.cc
+++ b/webrtc/modules/congestion_controller/congestion_controller.cc
@@ -170,6 +170,7 @@ CongestionController::CongestionController(
           new RateLimiter(clock, kRetransmitWindowSizeMs)),
       remote_estimator_proxy_(clock_, packet_router_.get()),
       transport_feedback_adapter_(bitrate_controller_.get(), clock_),
+      start_bitrate_bps_(0),
       min_bitrate_bps_(RemoteBitrateEstimator::kDefaultMinBitrateBps),
       max_bitrate_bps_(0),
       last_reported_bitrate_bps_(0),
@@ -228,14 +229,18 @@ void CongestionController::SetBweBitrates(int min_bitrate_bps,
                                    min_bitrate_bps,
                                    max_bitrate_bps);
 
+  if (start_bitrate_bps > 0)
+    start_bitrate_bps_ = start_bitrate_bps;
   {
     // Only do probing if:
     //   - we are mid-call, which we consider to be if

[philipel, 2016/08/23 10:55:28]

Nit: remove the last '-' since this is no longer a list.

-    //     |last_reported_bitrate_bps_| != 0, and
-    //   - the current bitrate is lower than the new |max_bitrate_bps|, and
-    //   - we actually want to increase the |max_bitrate_bps_|.
+    //     |last_reported_bitrate_bps_| is valid (> 0) and
+    //     |last_reported_bitrate_bps_| != |start_bitrate_bps_|, and
+    //     the current bitrate is lower than the new |max_bitrate_bps|, and
+    //     we actually want to increase the |max_bitrate_bps_|.
     rtc::CritScope cs(&critsect_);
-    if (last_reported_bitrate_bps_ != 0 &&
+    if (last_reported_bitrate_bps_ &&
+        last_reported_bitrate_bps_ != start_bitrate_bps_ &&
         last_reported_bitrate_bps_ < max_bitrate_bps &&
         max_bitrate_bps > max_bitrate_bps_) {
       pacer_->CreateProbeCluster(max_bitrate_bps, 5);