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.cc

@@ -0,0 +1,80 @@
+/*
+ *  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.
+ */
+
+#include "modules/audio_processing/aec3/render_buffer.h"
+
+#include <algorithm>
+#include <functional>
+
+#include "modules/audio_processing/aec3/aec3_common.h"
+#include "rtc_base/checks.h"
+
+namespace webrtc {
+
+RenderBuffer::RenderBuffer(BlockBuffer* block_buffer,
+                           SpectrumBuffer* spectrum_buffer,
+                           FftBuffer* fft_buffer)
+    : block_buffer_(block_buffer),
+      spectrum_buffer_(spectrum_buffer),
+      fft_buffer_(fft_buffer) {
+  RTC_DCHECK(block_buffer_);
+  RTC_DCHECK(spectrum_buffer_);
+  RTC_DCHECK(fft_buffer_);
+  RTC_DCHECK_EQ(block_buffer_->buffer.size(), fft_buffer_->buffer.size());
+  RTC_DCHECK_EQ(spectrum_buffer_->buffer.size(), fft_buffer_->buffer.size());
+  RTC_DCHECK_EQ(spectrum_buffer_->read, fft_buffer_->read);
+  RTC_DCHECK_EQ(spectrum_buffer_->write, fft_buffer_->write);
+}
+
+RenderBuffer::~RenderBuffer() = default;
+
+void RenderBuffer::SpectralSum(
+    size_t num_spectra,
+    std::array<float, kFftLengthBy2Plus1>* X2) const {
+  X2->fill(0.f);
+  int position = spectrum_buffer_->read;
+  for (size_t j = 0; j < num_spectra; ++j) {
+    for (const auto& channel_spectrum : spectrum_buffer_->buffer[position]) {
+      std::transform(X2->begin(), X2->end(), channel_spectrum.begin(),
+                     X2->begin(), std::plus<float>());
+    }
+    position = spectrum_buffer_->IncIndex(position);
+  }
+}
+
+void RenderBuffer::SpectralSums(
+    size_t num_spectra_shorter,
+    size_t num_spectra_longer,
+    std::array<float, kFftLengthBy2Plus1>* X2_shorter,
+    std::array<float, kFftLengthBy2Plus1>* X2_longer) const {
+  RTC_DCHECK_LE(num_spectra_shorter, num_spectra_longer);
+  X2_shorter->fill(0.f);
+  int position = spectrum_buffer_->read;
+  size_t j = 0;
+  for (; j < num_spectra_shorter; ++j) {
+    for (const auto& channel_spectrum : spectrum_buffer_->buffer[position]) {
+      std::transform(X2_shorter->begin(), X2_shorter->end(),
+                     channel_spectrum.begin(), X2_shorter->begin(),
+                     std::plus<float>());
+    }
+    position = spectrum_buffer_->IncIndex(position);
+  }
+  std::copy(X2_shorter->begin(), X2_shorter->end(), X2_longer->begin());
+  for (; j < num_spectra_longer; ++j) {
+    for (const auto& channel_spectrum : spectrum_buffer_->buffer[position]) {
+      std::transform(X2_longer->begin(), X2_longer->end(),
+                     channel_spectrum.begin(), X2_longer->begin(),
+                     std::plus<float>());
+    }
+    position = spectrum_buffer_->IncIndex(position);
+  }
+}
+
+}  // namespace webrtc