Reland of move RTPPayloadStrategy and simplify RTPPayloadRegistry

webrtc/modules/rtp_rtcp/source/rtp_receiver_audio.h

Index: webrtc/modules/rtp_rtcp/source/rtp_receiver_audio.h
diff --git a/webrtc/modules/rtp_rtcp/source/rtp_receiver_audio.h b/webrtc/modules/rtp_rtcp/source/rtp_receiver_audio.h
index 15d0bdeae671c4168c26f0c9ac9aa8c7c825e19c..5fbf738b4b7de4085de16e531a2e75a25ff847b1 100644
--- a/webrtc/modules/rtp_rtcp/source/rtp_receiver_audio.h
+++ b/webrtc/modules/rtp_rtcp/source/rtp_receiver_audio.h
@@ -64,16 +64,6 @@ class RTPReceiverAudio : public RTPReceiverStrategy,
       const char payload_name[RTP_PAYLOAD_NAME_SIZE],
       const PayloadUnion& specific_payload) const override;
 
-  // We do not allow codecs to have multiple payload types for audio, so we
-  // need to override the default behavior (which is to do nothing).
-  void PossiblyRemoveExistingPayloadType(
-      RtpUtility::PayloadTypeMap* payload_type_map,
-      const char payload_name[RTP_PAYLOAD_NAME_SIZE],
-      size_t payload_name_length,
-      uint32_t frequency,
-      uint8_t channels,
-      uint32_t rate) const;
-
   // We need to look out for special payload types here and sometimes reset
   // statistics. In addition we sometimes need to tweak the frequency.
   void CheckPayloadChanged(int8_t payload_type,
@@ -89,8 +79,6 @@ class RTPReceiverAudio : public RTPReceiverStrategy,
                                   const AudioPayload& audio_specific,
                                   bool is_red);
 
-  uint32_t last_received_frequency_;
-
   bool telephone_event_forward_to_decoder_;
   int8_t telephone_event_payload_type_;
   std::set<uint8_t> telephone_event_reported_;