Revert of Added first layer of the echo canceller 3 functionality

webrtc/modules/audio_processing/aec3/aec3_constants.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_PROCESSING_AEC3_AEC3_CONSTANTS_H_
-#define WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_AEC3_CONSTANTS_H_
-
-#include <stddef.h>
-
-namespace webrtc {
-
-constexpr size_t kFftLengthBy2 = 64;
-constexpr size_t kFftLengthBy2Plus1 = kFftLengthBy2 + 1;
-constexpr size_t kFftLength = 2 * kFftLengthBy2;
-
-constexpr size_t kMaxNumBands = 3;
-constexpr size_t kSubFrameLength = 80;
-
-constexpr size_t kBlockSize = kFftLengthBy2;
-constexpr size_t kExtendedBlockSize = 2 * kFftLengthBy2;
-constexpr size_t kSubBlockSize = 16;
-
-constexpr size_t NumBandsForRate(int sample_rate_hz) {
-  return static_cast<size_t>(sample_rate_hz == 8000 ? 1
-                                                    : sample_rate_hz / 16000);
-}
-constexpr int LowestBandRate(int sample_rate_hz) {
-  return sample_rate_hz == 8000 ? sample_rate_hz : 16000;
-}
-
-static_assert(1 == NumBandsForRate(8000), "Number of bands for 8 kHz");
-static_assert(1 == NumBandsForRate(16000), "Number of bands for 16 kHz");
-static_assert(2 == NumBandsForRate(32000), "Number of bands for 32 kHz");
-static_assert(3 == NumBandsForRate(48000), "Number of bands for 48 kHz");
-
-static_assert(8000 == LowestBandRate(8000), "Sample rate of band 0 for 8 kHz");
-static_assert(16000 == LowestBandRate(16000),
-              "Sample rate of band 0 for 16 kHz");
-static_assert(16000 == LowestBandRate(32000),
-              "Sample rate of band 0 for 32 kHz");
-static_assert(16000 == LowestBandRate(48000),
-              "Sample rate of band 0 for 48 kHz");
-
-}  // namespace webrtc
-
-#endif  // WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_AEC3_CONSTANTS_H_