Handle padded audio packets correctly

webrtc/modules/audio_coding/neteq/delay_manager.cc

Index: webrtc/modules/audio_coding/neteq/delay_manager.cc
diff --git a/webrtc/modules/audio_coding/neteq/delay_manager.cc b/webrtc/modules/audio_coding/neteq/delay_manager.cc
index 1f6cb0543ccf040c875a51419ee0f2ecf9903002..2941126c02c5e113d7ebb0c41f63b127721bf145 100644
--- a/webrtc/modules/audio_coding/neteq/delay_manager.cc
+++ b/webrtc/modules/audio_coding/neteq/delay_manager.cc
@@ -374,6 +374,10 @@ void DelayManager::LastDecodedWasCngOrDtmf(bool it_was) {
   }
 }
 
+void DelayManager::RegisterEmptyPacket() {
+  ++last_seq_no_;
+}
+
 bool DelayManager::SetMinimumDelay(int delay_ms) {
   // Minimum delay shouldn't be more than maximum delay, if any maximum is set.
   // Also, if possible check |delay| to less than 75% of