NetEq: Add functionality to assist with delay analysis and tooling

webrtc/modules/audio_coding/neteq/neteq_impl_unittest.cc

Index: webrtc/modules/audio_coding/neteq/neteq_impl_unittest.cc
diff --git a/webrtc/modules/audio_coding/neteq/neteq_impl_unittest.cc b/webrtc/modules/audio_coding/neteq/neteq_impl_unittest.cc
index 4e110a612d0f0c66b51f02e09698ba7a18fd1695..fb87111fd07b39e9546b69bc86269100cf50c704 100644
--- a/webrtc/modules/audio_coding/neteq/neteq_impl_unittest.cc
+++ b/webrtc/modules/audio_coding/neteq/neteq_impl_unittest.cc
@@ -1271,6 +1271,19 @@ TEST_F(NetEqImplTest, TickTimerIncrement) {
   EXPECT_EQ(1u, tick_timer_->ticks());
 }
 
+TEST_F(NetEqImplTest, TargetDelayMs) {
+  UseNoMocks();
+  use_mock_delay_manager_ = true;
+  CreateInstance();
+  // Let the dummy target delay be 17 packets.
+  constexpr int kTargetLevelPacketsQ8 = 17 << 8;
+  EXPECT_CALL(*mock_delay_manager_, TargetLevel())
+      .WillOnce(Return(kTargetLevelPacketsQ8));
+  // Default packet size before any packet has been decoded is 30 ms, so we are
+  // expecting 17 * 30 = 510 ms target delay.
+  EXPECT_EQ(17 * 30, neteq_->TargetDelayMs());
+}
+
 class Decoder120ms : public AudioDecoder {
  public:
   Decoder120ms(int sample_rate_hz, SpeechType speech_type)