Refactoring PayloadRouter.

- Move PayloadRouter to RtpTransportControllerInterface.
- Move RetransmissionLimiter inside RtpTransportControllerSend from
  VideoSendStreamImpl.
- Move video RTP specifics into PayloadRouter, in particular ownership
  of the RTP modules.
- PayloadRouter now contains all video specific RTP code, and will be
  renamed in a follow-up to VideoRtpSender.
- Introduce VideoRtpSenderInterface.

Bug: webrtc:9517
Change-Id: I1c7b293fa6f9c320286c80533b3c584498034a38
Reviewed-on: https://webrtc-review.googlesource.com/88240
Commit-Queue: Stefan Holmer <stefan@webrtc.org>
Reviewed-by: Sebastian Jansson <srte@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24009}
diff --git a/modules/video_coding/decoder_database.h b/modules/video_coding/decoder_database.h
index c3779c5..8c96b41 100644
--- a/modules/video_coding/decoder_database.h
+++ b/modules/video_coding/decoder_database.h
@@ -23,6 +23,7 @@
   VCMDecoderMapItem(VideoCodec* settings,
                     int number_of_cores,
                     bool require_key_frame);
+  ~VCMDecoderMapItem();
 
   std::unique_ptr<VideoCodec> settings;
   int number_of_cores;