Convert CNG into C++ and remove it from AudioDecoder

webrtc/modules/audio_coding/neteq/audio_decoder_impl.h

 /*
  *  Copyright (c) 2012 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.
  */
 
 #ifndef WEBRTC_MODULES_AUDIO_CODING_NETEQ_AUDIO_DECODER_IMPL_H_
 #define WEBRTC_MODULES_AUDIO_CODING_NETEQ_AUDIO_DECODER_IMPL_H_
 
 #include <assert.h>
 
 #include "webrtc/engine_configurations.h"
 #include "webrtc/base/constructormagic.h"
 #include "webrtc/modules/audio_coding/codecs/audio_decoder.h"
 #include "webrtc/modules/audio_coding/codecs/cng/webrtc_cng.h"
 #ifdef WEBRTC_CODEC_G722
 #include "webrtc/modules/audio_coding/codecs/g722/g722_interface.h"
 #endif
 #include "webrtc/modules/audio_coding/acm2/rent_a_codec.h"
 #include "webrtc/typedefs.h"
 
 namespace webrtc {
 
-// AudioDecoderCng is a special type of AudioDecoder. It inherits from
-// AudioDecoder just to fit in the DecoderDatabase. None of the class methods
-// should be used, except constructor, destructor, and accessors.
-// TODO(hlundin): Consider the possibility to create a super-class to
-// AudioDecoder that is stored in DecoderDatabase. Then AudioDecoder and a
-// specific CngDecoder class could both inherit from that class.
-class AudioDecoderCng : public AudioDecoder {
- public:
-  explicit AudioDecoderCng();
-  ~AudioDecoderCng() override;
-  void Reset() override;
-  int IncomingPacket(const uint8_t* payload,
-                     size_t payload_len,
-                     uint16_t rtp_sequence_number,
-                     uint32_t rtp_timestamp,
-                     uint32_t arrival_timestamp) override;
-
-  CNG_dec_inst* CngDecoderInstance() override;
-  size_t Channels() const override;
-
- protected:
-  int DecodeInternal(const uint8_t* encoded,
-                     size_t encoded_len,
-                     int sample_rate_hz,
-                     int16_t* decoded,
-                     SpeechType* speech_type) override;
-
- private:
-  CNG_dec_inst* dec_state_;
-  RTC_DISALLOW_COPY_AND_ASSIGN(AudioDecoderCng);
-};
-
 using NetEqDecoder = acm2::RentACodec::NetEqDecoder;
 
 // Returns true if |codec_type| is supported.
 bool CodecSupported(NetEqDecoder codec_type);
 
 // Returns the sample rate for |codec_type|.
 int CodecSampleRateHz(NetEqDecoder codec_type);
 
 // Creates an AudioDecoder object of type |codec_type|. Returns NULL for for
 // unsupported codecs, and when creating an AudioDecoder is not applicable
 // (e.g., for RED and DTMF/AVT types).
 AudioDecoder* CreateAudioDecoder(NetEqDecoder codec_type);
 
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_AUDIO_CODING_NETEQ_AUDIO_DECODER_IMPL_H_