Delete full-band mode from the iSAC codec

webrtc/modules/audio_coding/codecs/isac/audio_decoder_isac_t_impl.h

 /*
  *  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 26 matching lines @@
 AudioDecoderIsacT<T>::~AudioDecoderIsacT() {
   RTC_CHECK_EQ(0, T::Free(isac_state_));
 }
 
 template <typename T>
 int AudioDecoderIsacT<T>::DecodeInternal(const uint8_t* encoded,
                                          size_t encoded_len,
                                          int sample_rate_hz,
                                          int16_t* decoded,
                                          SpeechType* speech_type) {
-  // We want to crate the illusion that iSAC supports 48000 Hz decoding, while
-  // in fact it outputs 32000 Hz. This is the iSAC fullband mode.
-  if (sample_rate_hz == 48000)
-    sample_rate_hz = 32000;
   RTC_CHECK(sample_rate_hz == 16000 || sample_rate_hz == 32000)
       << "Unsupported sample rate " << sample_rate_hz;
   if (sample_rate_hz != decoder_sample_rate_hz_) {
     RTC_CHECK_EQ(0, T::SetDecSampRate(isac_state_, sample_rate_hz));
     decoder_sample_rate_hz_ = sample_rate_hz;
   }
   int16_t temp_type = 1;  // Default is speech.
   int ret =
       T::DecodeInternal(isac_state_, encoded, encoded_len, decoded, &temp_type);
   *speech_type = ConvertSpeechType(temp_type);
@@ skipping 38 matching lines @@
 }
 
 template <typename T>
 size_t AudioDecoderIsacT<T>::Channels() const {
   return 1;
 }
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_AUDIO_CODING_CODECS_ISAC_AUDIO_DECODER_ISAC_T_IMPL_H_