Handle BW drop in ALR region and initiate probing

webrtc/modules/pacing/paced_sender.cc

Index: webrtc/modules/pacing/paced_sender.cc
diff --git a/webrtc/modules/pacing/paced_sender.cc b/webrtc/modules/pacing/paced_sender.cc
index 6c5e183a7807f7d517c531ba6904f7e183a52233..d38154a2416e66db5ab42d81c68687a8afe8b9af 100644
--- a/webrtc/modules/pacing/paced_sender.cc
+++ b/webrtc/modules/pacing/paced_sender.cc
@@ -343,6 +343,11 @@ int64_t PacedSender::ExpectedQueueTimeMs() const {
                               pacing_bitrate_kbps_);
 }
 
+bool PacedSender::InApplicationLimitedRegion() const {
+  CriticalSectionScoped cs(critsect_.get());
+  return alr_detector_->InApplicationLimitedRegion();
+}
+
 size_t PacedSender::QueueSizePackets() const {
   CriticalSectionScoped cs(critsect_.get());
   return packets_->SizeInPackets();