Implement RTCInboundRTPStreamStats.JitterBufferMinimumDelay

This metric was recently added to the standard (see https://w3c.github.io/webrtc-stats/#dom-rtcinboundrtpstreamstats-jitterbufferminimumdelay). This CL implements it for audio streams.

Bug: webrtc:14141
Change-Id: I79d918639cd12361ebbc28c2be41549e33fa7e2a
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/262770
Reviewed-by: Tomas Gunnarsson <tommi@webrtc.org>
Reviewed-by: Jakob Ivarsson‎ <jakobi@webrtc.org>
Reviewed-by: Henrik Boström <hbos@webrtc.org>
Commit-Queue: Ivo Creusen <ivoc@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#37567}
diff --git a/modules/audio_coding/neteq/delay_manager.cc b/modules/audio_coding/neteq/delay_manager.cc
index ba8f706..bf3a0f1 100644
--- a/modules/audio_coding/neteq/delay_manager.cc
+++ b/modules/audio_coding/neteq/delay_manager.cc
@@ -101,6 +101,7 @@
     target_level_ms_ = std::max(
         target_level_ms_, reorder_optimizer_->GetOptimalDelayMs().value_or(0));
   }
+  unlimited_target_level_ms_ = target_level_ms_;
   target_level_ms_ = std::max(target_level_ms_, effective_minimum_delay_ms_);
   if (maximum_delay_ms_ > 0) {
     target_level_ms_ = std::min(target_level_ms_, maximum_delay_ms_);
@@ -134,6 +135,10 @@
   return target_level_ms_;
 }
 
+int DelayManager::UnlimitedTargetLevelMs() const {
+  return unlimited_target_level_ms_;
+}
+
 bool DelayManager::IsValidMinimumDelay(int delay_ms) const {
   return 0 <= delay_ms && delay_ms <= MinimumDelayUpperBound();
 }