Move the FEC enabling logic from CodecManager to Rent-A-Codec

webrtc/modules/audio_coding/main/acm2/rent_a_codec.cc

 /*
  *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 235 matching lines @@
     RentACodec::RegisterRedPayloadType(&red_payload_types, ci);
   }
 }
 
 RentACodec::StackParameters::~StackParameters() = default;
 
 AudioEncoder* RentACodec::RentEncoderStack(AudioEncoder* speech_encoder,
                                            StackParameters* param) {
   RTC_DCHECK(speech_encoder);
 
+  if (param->use_codec_fec) {
+    // Switch FEC on. On failure, remember that FEC is off.
+    if (!speech_encoder->SetFec(true))
+      param->use_codec_fec = false;
+  } else {
+    // Switch FEC off. This shouldn't fail.
+    const bool success = speech_encoder->SetFec(false);
+    RTC_DCHECK(success);
+  }
+
   auto pt = [&speech_encoder](const std::map<int, int>& m) {
     auto it = m.find(speech_encoder->SampleRateHz());
     return it == m.end() ? rtc::Optional<int>()
                          : rtc::Optional<int>(it->second);
   };
   auto cng_pt = pt(param->cng_payload_types);
   param->use_cng =
       param->use_cng && cng_pt && speech_encoder->NumChannels() == 1;
   auto red_pt = pt(param->red_payload_types);
   param->use_red = param->use_red && red_pt;
@@ skipping 21 matching lines @@
 }
 
 AudioDecoder* RentACodec::RentIsacDecoder() {
   if (!isac_decoder_)
     isac_decoder_ = CreateIsacDecoder(&isac_bandwidth_info_);
   return isac_decoder_.get();
 }
 
 }  // namespace acm2
 }  // namespace webrtc