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

webrtc/modules/audio_processing/beamformer/nonlinear_beamformer.cc

Index: webrtc/modules/audio_processing/beamformer/nonlinear_beamformer.cc
diff --git a/webrtc/modules/audio_processing/beamformer/nonlinear_beamformer.cc b/webrtc/modules/audio_processing/beamformer/nonlinear_beamformer.cc
index 66ad6259a3690c31f96668c6d9c206ed1ae9cca7..6925b617624579bcc70804b25ef1456af88757cf 100644
--- a/webrtc/modules/audio_processing/beamformer/nonlinear_beamformer.cc
+++ b/webrtc/modules/audio_processing/beamformer/nonlinear_beamformer.cc
@@ -120,7 +120,7 @@ complex<float> ConjugateDotProduct(const ComplexMatrix<float>& lhs,
 
 // 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.
@@ -464,9 +464,9 @@ void NonlinearBeamformer::ApplyMaskFrequencySmoothing() {
     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];

[Peter Kasting, 2015/07/10 18:48:46]

This form is safe against underflow if |i| becomes size_t.

   }
 }