Added RTCMediaStreamTrackStats.jitterBufferDelay for audio

Description of this stat can be found here:
https://w3c.github.io/webrtc-stats/#dom-rtcmediastreamtrackstats-jitterbufferdelay

Bug: webrtc:8281
Change-Id: Ib2e8174f3449e68ad419ae2d58d5565fc9854023
Reviewed-on: https://webrtc-review.googlesource.com/3381
Commit-Queue: Gustaf Ullberg <gustaf@webrtc.org>
Reviewed-by: Henrik Boström <hbos@webrtc.org>
Reviewed-by: Taylor Brandstetter <deadbeef@webrtc.org>
Reviewed-by: Fredrik Solenberg <solenberg@webrtc.org>
Reviewed-by: Henrik Lundin <henrik.lundin@webrtc.org>
Reviewed-by: Henrik Andreassson <henrika@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20069}
diff --git a/audio/audio_receive_stream_unittest.cc b/audio/audio_receive_stream_unittest.cc
index 1ceaaab..4fdb68c 100644
--- a/audio/audio_receive_stream_unittest.cc
+++ b/audio/audio_receive_stream_unittest.cc
@@ -64,9 +64,9 @@
     345,  678,  901, 234, -12, 3456, 7890, 567, 890, 123};
 const CodecInst kCodecInst = {
     123, "codec_name_recv", 96000, -187, 0, -103};
-const NetworkStatistics kNetworkStats = {123, 456, false, 789012, 3456, 123, 0,
-                                         {},  789, 12,    345,    678,  901, 0,
-                                         -1,  -1,  -1,    -1,     -1,   0};
+const NetworkStatistics kNetworkStats = {
+    123, 456, false, 789012, 3456, 123, 456, 0,  {}, 789, 12,
+    345, 678, 901,   0,      -1,   -1,  -1,  -1, -1, 0};
 const AudioDecodingCallStats kAudioDecodeStats = MakeAudioDecodeStatsForTest();
 
 struct ConfigHelper {
@@ -316,6 +316,9 @@
   EXPECT_EQ(kTotalOutputDuration, stats.total_output_duration);
   EXPECT_EQ(kNetworkStats.concealedSamples, stats.concealed_samples);
   EXPECT_EQ(kNetworkStats.concealmentEvents, stats.concealment_events);
+  EXPECT_EQ(static_cast<double>(kNetworkStats.jitterBufferDelayMs) /
+                static_cast<double>(rtc::kNumMillisecsPerSec),
+            stats.jitter_buffer_delay_seconds);
   EXPECT_EQ(Q14ToFloat(kNetworkStats.currentExpandRate), stats.expand_rate);
   EXPECT_EQ(Q14ToFloat(kNetworkStats.currentSpeechExpandRate),
             stats.speech_expand_rate);