Miscellaneous changes split from https://codereview.webrtc.org/1230503003 .

webrtc/modules/audio_processing/beamformer/nonlinear_beamformer.cc

 /*
  *  Copyright (c) 2014 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.
  */
 
@@ skipping 102 matching lines @@
   complex<float> result = complex<float>(0.f, 0.f);
   for (int i = 0; i < lhs.num_columns(); ++i) {
     result += conj(lhs_elements[0][i]) * rhs_elements[0][i];
   }
 
   return result;
 }
 
 // Works for positive numbers only.
 int Round(float x) {
-  return std::floor(x + 0.5f);
+  return static_cast<int>(std::floor(x + 0.5f));
 }
 
 // Calculates the sum of absolute values of a complex matrix.
 float SumAbs(const ComplexMatrix<float>& mat) {
   float sum_abs = 0.f;
   const complex<float>* const* mat_els = mat.elements();
   for (int i = 0; i < mat.num_rows(); ++i) {
     for (int j = 0; j < mat.num_columns(); ++j) {
       sum_abs += std::abs(mat_els[i][j]);
     }
@@ skipping 323 matching lines @@
   // Downward smoothing:
   //         high_mean_end_bin_
   //                    v
   // |------|------------|------|
   //  ^<------------------^
   std::copy(time_smooth_mask_, time_smooth_mask_ + kNumFreqBins, final_mask_);
   for (int i = low_mean_start_bin_; i < kNumFreqBins; ++i) {
     final_mask_[i] = kMaskFrequencySmoothAlpha * final_mask_[i] +
                      (1 - kMaskFrequencySmoothAlpha) * final_mask_[i - 1];
   }
-  for (int i = high_mean_end_bin_; i >= 0; --i) {
-    final_mask_[i] = kMaskFrequencySmoothAlpha * final_mask_[i] +
-                     (1 - kMaskFrequencySmoothAlpha) * final_mask_[i + 1];
+  for (int i = high_mean_end_bin_ + 1; i > 0; --i) {
+    final_mask_[i - 1] = kMaskFrequencySmoothAlpha * final_mask_[i - 1] +
+                         (1 - kMaskFrequencySmoothAlpha) * final_mask_[i];
   }
 }
 
 // Apply low frequency correction to time_smooth_mask_.
 void NonlinearBeamformer::ApplyLowFrequencyCorrection() {
   const float low_frequency_mask =
       MaskRangeMean(low_mean_start_bin_, low_mean_end_bin_ + 1);
   std::fill(time_smooth_mask_, time_smooth_mask_ + low_mean_start_bin_,
             low_frequency_mask);
 }
@@ skipping 23 matching lines @@
                    new_mask_ + high_mean_end_bin_ + 1);
   if (new_mask_[quantile] > kMaskTargetThreshold) {
     is_target_present_ = true;
     interference_blocks_count_ = 0;
   } else {
     is_target_present_ = interference_blocks_count_++ < hold_target_blocks_;
   }
 }
 
 }  // namespace webrtc