Initiate mid-call probing even if estimated bitrate is at max configured bitrate.

webrtc/modules/congestion_controller/probe_controller.cc

Index: webrtc/modules/congestion_controller/probe_controller.cc
diff --git a/webrtc/modules/congestion_controller/probe_controller.cc b/webrtc/modules/congestion_controller/probe_controller.cc
index bf81517b7044d33be4ecd3fcf38896df8ff560b6..f7f42aa9b988d86f6c811cf144929ada4f0795ea 100644
--- a/webrtc/modules/congestion_controller/probe_controller.cc
+++ b/webrtc/modules/congestion_controller/probe_controller.cc
@@ -71,6 +71,8 @@ void ProbeController::SetBitrates(int64_t min_bitrate_bps,
     start_bitrate_bps_ = min_bitrate_bps;
   }
 
+  // The reason we set use the variable |old_max_bitrate_pbs| is because we

[stefan-webrtc, 2017/01/16 13:23:59]

-set

[philipel, 2017/01/16 13:59:28]

Done.

+  // need to set |max_bitrate_bps_| before we call InitiateProbing.
   int64_t old_max_bitrate_bps = max_bitrate_bps_;
   max_bitrate_bps_ = max_bitrate_bps;
 
@@ -84,10 +86,11 @@ void ProbeController::SetBitrates(int64_t min_bitrate_bps,
       break;
 
     case State::kProbingComplete:
-      // Initiate probing when |max_bitrate_| was increased mid-call.
-      if (estimated_bitrate_bps_ != kExponentialProbingDisabled &&
-          estimated_bitrate_bps_ < old_max_bitrate_bps &&
-          max_bitrate_bps_ > old_max_bitrate_bps) {
+      // If the new max bitrate is higher than the old max bitrate and the
+      // estimate is lower than the new max bitrate then initiate probing.
+      if (estimated_bitrate_bps_ != 0 &&

[stefan-webrtc, 2017/01/16 13:23:59]

Should probably still compare with kExponentialProbingDisabled?

[philipel, 2017/01/16 13:59:28]

This logic is not related to exponential probing, so it doesn't make sense to
use kExponentialProbingDisabled here.

+          old_max_bitrate_bps < max_bitrate_bps_ &&
+          estimated_bitrate_bps_ < max_bitrate_bps_) {
         InitiateProbing(clock_->TimeInMilliseconds(), {max_bitrate_bps}, false);
       }
       break;