Remove webrtc::VideoDecoder::PrefersLateDecoding.

This is just general cleanup.

The assumed behavior is late decoding, and this function is not used to make any decision (except in the deprecated jitter buffer).

Bug: webrtc:12271
Change-Id: Ifb48186d55903f068f25e44c5f73e7a724f6f456
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/200804
Commit-Queue: Philip Eliasson <philipel@webrtc.org>
Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
Reviewed-by: Christoffer Rodbro <crodbro@webrtc.org>
Reviewed-by: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#32940}
diff --git a/api/video_codecs/video_decoder.h b/api/video_codecs/video_decoder.h
index 266d653..155e76c 100644
--- a/api/video_codecs/video_decoder.h
+++ b/api/video_codecs/video_decoder.h
@@ -59,6 +59,7 @@
   // Returns true if the decoder prefer to decode frames late.
   // That is, it can not decode infinite number of frames before the decoded
   // frame is consumed.
+  // TODO(bugs.webrtc.org/12271): Remove when downstream has been updated.
   virtual bool PrefersLateDecoding() const;
 
   virtual const char* ImplementationName() const;