Revert of Moved the ringbuffer to be built using C++

webrtc/modules/audio_processing/aec/aec_core_internal.h

 /*
  *  Copyright (c) 2013 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_PROCESSING_AEC_AEC_CORE_INTERNAL_H_
 #define WEBRTC_MODULES_AUDIO_PROCESSING_AEC_AEC_CORE_INTERNAL_H_
 
 #include "webrtc/common_audio/wav_file.h"
 #include "webrtc/modules/audio_processing/aec/aec_common.h"
 #include "webrtc/modules/audio_processing/aec/aec_core.h"
 #include "webrtc/modules/audio_processing/utility/block_mean_calculator.h"
+extern "C" {
 #include "webrtc/modules/audio_processing/utility/ring_buffer.h"
+}
 
 #include "webrtc/typedefs.h"
 
 namespace webrtc {
 
 // Number of partitions for the extended filter mode. The first one is an enum
 // to be used in array declarations, as it represents the maximum filter length.
 enum { kExtendedNumPartitions = 32 };
 static const int kNormalNumPartitions = 12;
 
@@ skipping 196 matching lines @@
 typedef void (*WebRtcAecStoreAsComplex)(const float* data,
                                         float data_complex[2][PART_LEN1]);
 extern WebRtcAecStoreAsComplex WebRtcAec_StoreAsComplex;
 
 typedef void (*WebRtcAecWindowData)(float* x_windowed, const float* x);
 extern WebRtcAecWindowData WebRtcAec_WindowData;
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_AUDIO_PROCESSING_AEC_AEC_CORE_INTERNAL_H_