Revert of AcmReceiver: Look up last decoder in NetEq's table of decoders

webrtc/modules/audio_coding/neteq/neteq_impl.cc

Index: webrtc/modules/audio_coding/neteq/neteq_impl.cc
diff --git a/webrtc/modules/audio_coding/neteq/neteq_impl.cc b/webrtc/modules/audio_coding/neteq/neteq_impl.cc
index 71eea2114c2d3892e13d160ba43d8e700e20dea7..9c4f5809068f8964ef74882c0414f184ce37eef0 100644
--- a/webrtc/modules/audio_coding/neteq/neteq_impl.cc
+++ b/webrtc/modules/audio_coding/neteq/neteq_impl.cc
@@ -431,27 +431,6 @@
   return last_output_sample_rate_hz_;
 }
 
-rtc::Optional<CodecInst> NetEqImpl::GetDecoder(int payload_type) const {
-  rtc::CritScope lock(&crit_sect_);
-  const DecoderDatabase::DecoderInfo* di =
-      decoder_database_->GetDecoderInfo(payload_type);
-  if (!di) {
-    return rtc::Optional<CodecInst>();
-  }
-
-  // Create a CodecInst with some fields set. The remaining fields are zeroed,
-  // but we tell MSan to consider them uninitialized.
-  CodecInst ci = {0};
-  rtc::MsanMarkUninitialized(rtc::MakeArrayView(&ci, 1));
-  ci.pltype = payload_type;
-  std::strncpy(ci.plname, di->name.c_str(), sizeof(ci.plname));
-  ci.plname[sizeof(ci.plname) - 1] = '\0';
-  ci.plfreq = di->IsRed() || di->IsDtmf() ? 8000 : di->SampleRateHz();
-  AudioDecoder* const decoder = di->GetDecoder();
-  ci.channels = decoder ? decoder->Channels() : 1;
-  return rtc::Optional<CodecInst>(ci);
-}
-
 int NetEqImpl::SetTargetNumberOfChannels() {
   return kNotImplemented;
 }