Expose delayed packet outage as a cumulative metric of samples in the new getStats API.

The stat will be exposed through origin trial described in:
https://docs.google.com/document/d/1stYIZhEmDZ7NJF9gjjsM66eLFJUdc-14a3QutrFbIwI

Change-Id: Ib191a11c6bd9e617abbe9dd82239b0c5b4e6b4e0
Bug: webrtc:10043
Reviewed-on: https://webrtc-review.googlesource.com/c/111922
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Ivo Creusen <ivoc@webrtc.org>
Reviewed-by: Henrik Lundin <henrik.lundin@webrtc.org>
Reviewed-by: Minyue Li <minyue@webrtc.org>
Commit-Queue: Jakob Ivarsson‎ <jakobi@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25802}
diff --git a/modules/audio_coding/acm2/acm_receiver.cc b/modules/audio_coding/acm2/acm_receiver.cc
index d02e50d..d3af7c0 100644
--- a/modules/audio_coding/acm2/acm_receiver.cc
+++ b/modules/audio_coding/acm2/acm_receiver.cc
@@ -345,6 +345,8 @@
   acm_stat->concealedSamples = neteq_lifetime_stat.concealed_samples;
   acm_stat->concealmentEvents = neteq_lifetime_stat.concealment_events;
   acm_stat->jitterBufferDelayMs = neteq_lifetime_stat.jitter_buffer_delay_ms;
+  acm_stat->delayedPacketOutageSamples =
+      neteq_lifetime_stat.delayed_packet_outage_samples;
 
   NetEqOperationsAndState neteq_operations_and_state =
       neteq_->GetOperationsAndState();