Update to current webrtc library

This is from the upstream library commit id
3326535126e435f1ba647885ce43a8f0f3d317eb, corresponding to Chromium
88.0.4290.1.

webrtc/modules/audio_processing/aec3/render_buffer.h

@@ -0,0 +1,116 @@
+/*
+ *  Copyright (c) 2017 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 MODULES_AUDIO_PROCESSING_AEC3_RENDER_BUFFER_H_
+#define MODULES_AUDIO_PROCESSING_AEC3_RENDER_BUFFER_H_
+
+#include <stddef.h>
+
+#include <array>
+#include <vector>
+
+#include "api/array_view.h"
+#include "modules/audio_processing/aec3/aec3_common.h"
+#include "modules/audio_processing/aec3/block_buffer.h"
+#include "modules/audio_processing/aec3/fft_buffer.h"
+#include "modules/audio_processing/aec3/fft_data.h"
+#include "modules/audio_processing/aec3/spectrum_buffer.h"
+#include "rtc_base/checks.h"
+
+namespace webrtc {
+
+// Provides a buffer of the render data for the echo remover.
+class RenderBuffer {
+ public:
+  RenderBuffer(BlockBuffer* block_buffer,
+               SpectrumBuffer* spectrum_buffer,
+               FftBuffer* fft_buffer);
+
+  RenderBuffer() = delete;
+  RenderBuffer(const RenderBuffer&) = delete;
+  RenderBuffer& operator=(const RenderBuffer&) = delete;
+
+  ~RenderBuffer();
+
+  // Get a block.
+  const std::vector<std::vector<std::vector<float>>>& Block(
+      int buffer_offset_blocks) const {
+    int position =
+        block_buffer_->OffsetIndex(block_buffer_->read, buffer_offset_blocks);
+    return block_buffer_->buffer[position];
+  }
+
+  // Get the spectrum from one of the FFTs in the buffer.
+  rtc::ArrayView<const std::array<float, kFftLengthBy2Plus1>> Spectrum(
+      int buffer_offset_ffts) const {
+    int position = spectrum_buffer_->OffsetIndex(spectrum_buffer_->read,
+                                                 buffer_offset_ffts);
+    return spectrum_buffer_->buffer[position];
+  }
+
+  // Returns the circular fft buffer.
+  rtc::ArrayView<const std::vector<FftData>> GetFftBuffer() const {
+    return fft_buffer_->buffer;
+  }
+
+  // Returns the current position in the circular buffer.
+  size_t Position() const {
+    RTC_DCHECK_EQ(spectrum_buffer_->read, fft_buffer_->read);
+    RTC_DCHECK_EQ(spectrum_buffer_->write, fft_buffer_->write);
+    return fft_buffer_->read;
+  }
+
+  // Returns the sum of the spectrums for a certain number of FFTs.
+  void SpectralSum(size_t num_spectra,
+                   std::array<float, kFftLengthBy2Plus1>* X2) const;
+
+  // Returns the sums of the spectrums for two numbers of FFTs.
+  void SpectralSums(size_t num_spectra_shorter,
+                    size_t num_spectra_longer,
+                    std::array<float, kFftLengthBy2Plus1>* X2_shorter,
+                    std::array<float, kFftLengthBy2Plus1>* X2_longer) const;
+
+  // Gets the recent activity seen in the render signal.
+  bool GetRenderActivity() const { return render_activity_; }
+
+  // Specifies the recent activity seen in the render signal.
+  void SetRenderActivity(bool activity) { render_activity_ = activity; }
+
+  // Returns the headroom between the write and the read positions in the
+  // buffer.
+  int Headroom() const {
+    // The write and read indices are decreased over time.
+    int headroom =
+        fft_buffer_->write < fft_buffer_->read
+            ? fft_buffer_->read - fft_buffer_->write
+            : fft_buffer_->size - fft_buffer_->write + fft_buffer_->read;
+
+    RTC_DCHECK_LE(0, headroom);
+    RTC_DCHECK_GE(fft_buffer_->size, headroom);
+
+    return headroom;
+  }
+
+  // Returns a reference to the spectrum buffer.
+  const SpectrumBuffer& GetSpectrumBuffer() const { return *spectrum_buffer_; }
+
+  // Returns a reference to the block buffer.
+  const BlockBuffer& GetBlockBuffer() const { return *block_buffer_; }
+
+ private:
+  const BlockBuffer* const block_buffer_;
+  const SpectrumBuffer* const spectrum_buffer_;
+  const FftBuffer* const fft_buffer_;
+  bool render_activity_ = false;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AEC3_RENDER_BUFFER_H_