Move AudioDecoder and related stuff to the api/ directory

webrtc/modules/audio_coding/codecs/legacy_encoded_audio_frame.h

 /*
  *  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.
  */
 
 #ifndef WEBRTC_MODULES_AUDIO_CODING_CODECS_LEGACY_ENCODED_AUDIO_FRAME_H_
 #define WEBRTC_MODULES_AUDIO_CODING_CODECS_LEGACY_ENCODED_AUDIO_FRAME_H_
 
 #include <vector>
 
+#include "webrtc/api/audio_codecs/audio_decoder.h"
 #include "webrtc/base/array_view.h"
-#include "webrtc/modules/audio_coding/codecs/audio_decoder.h"
 
 namespace webrtc {
 
 class LegacyEncodedAudioFrame final : public AudioDecoder::EncodedAudioFrame {
  public:
   LegacyEncodedAudioFrame(AudioDecoder* decoder, rtc::Buffer&& payload);
   ~LegacyEncodedAudioFrame() override;
 
   static std::vector<AudioDecoder::ParseResult> SplitBySamples(
       AudioDecoder* decoder,
@@ skipping 11 matching lines @@
   const rtc::Buffer& payload() const { return payload_; }
 
  private:
   AudioDecoder* const decoder_;
   const rtc::Buffer payload_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_AUDIO_CODING_CODECS_LEGACY_ENCODED_AUDIO_FRAME_H_