NetEq: Change member variables for current RTP types to rtc::Optionals

webrtc/modules/audio_coding/neteq/neteq_impl.h

Index: webrtc/modules/audio_coding/neteq/neteq_impl.h
diff --git a/webrtc/modules/audio_coding/neteq/neteq_impl.h b/webrtc/modules/audio_coding/neteq/neteq_impl.h
index 91770c5995bf52c9fa9a5820f7d6b4371b0fbf67..f2f6419eb1dde582373b2e2f19276887fcee2d70 100644
--- a/webrtc/modules/audio_coding/neteq/neteq_impl.h
+++ b/webrtc/modules/audio_coding/neteq/neteq_impl.h
@@ -16,6 +16,7 @@
 
 #include "webrtc/base/constructormagic.h"
 #include "webrtc/base/criticalsection.h"
+#include "webrtc/base/optional.h"
 #include "webrtc/base/thread_annotations.h"
 #include "webrtc/modules/audio_coding/neteq/audio_multi_vector.h"
 #include "webrtc/modules/audio_coding/neteq/defines.h"
@@ -397,8 +398,8 @@ class NetEqImpl : public webrtc::NetEq {
   bool new_codec_ GUARDED_BY(crit_sect_);
   uint32_t timestamp_ GUARDED_BY(crit_sect_);
   bool reset_decoder_ GUARDED_BY(crit_sect_);
-  uint8_t current_rtp_payload_type_ GUARDED_BY(crit_sect_);
-  uint8_t current_cng_rtp_payload_type_ GUARDED_BY(crit_sect_);
+  rtc::Optional<uint8_t> current_rtp_payload_type_ GUARDED_BY(crit_sect_);
+  rtc::Optional<uint8_t> current_cng_rtp_payload_type_ GUARDED_BY(crit_sect_);
   uint32_t ssrc_ GUARDED_BY(crit_sect_);
   bool first_packet_ GUARDED_BY(crit_sect_);
   int error_code_ GUARDED_BY(crit_sect_);  // Store last error code.