Give Audio{De,En}coderIsac* an "Impl" suffix, to free up the original names

webrtc/modules/audio_coding/codecs/builtin_audio_decoder_factory_internal.cc

 /*
  *  Copyright (c) 2016 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 73 matching lines @@
        } else {
          return false;
        }
      }},
 #endif
 #if defined(WEBRTC_CODEC_ISACFX)
     {"isac",
      [](const SdpAudioFormat& format, std::unique_ptr<AudioDecoder>* out) {
        if (format.clockrate_hz == 16000 && format.num_channels == 1) {
          if (out) {
-           out->reset(new AudioDecoderIsacFix(format.clockrate_hz));
+           out->reset(new AudioDecoderIsacFixImpl(format.clockrate_hz));
          }
          return true;
        } else {
          return false;
        }
      }},
 #elif defined(WEBRTC_CODEC_ISAC)
     {"isac",
      [](const SdpAudioFormat& format, std::unique_ptr<AudioDecoder>* out) {
        if ((format.clockrate_hz == 16000 || format.clockrate_hz == 32000) &&
            format.num_channels == 1) {
          if (out) {
-           out->reset(new AudioDecoderIsac(format.clockrate_hz));
+           out->reset(new AudioDecoderIsacFloatImpl(format.clockrate_hz));
          }
          return true;
        } else {
          return false;
        }
      }},
 #endif
     {"l16",
      [](const SdpAudioFormat& format, std::unique_ptr<AudioDecoder>* out) {
        if (format.num_channels >= 1) {
@@ skipping 130 matching lines @@
 
 }  // namespace
 
 rtc::scoped_refptr<AudioDecoderFactory>
 CreateBuiltinAudioDecoderFactoryInternal() {
   return rtc::scoped_refptr<AudioDecoderFactory>(
       new rtc::RefCountedObject<BuiltinAudioDecoderFactory>);
 }
 
 }  // namespace webrtc