Fix error when accumulating floats in an int.

webrtc/modules/audio_processing/level_controller/level_controller.cc

 /*
  *  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.
  */
 
@@ skipping 17 matching lines @@
 #include "webrtc/system_wrappers/include/metrics.h"
 
 namespace webrtc {
 namespace {
 
 void UpdateAndRemoveDcLevel(float forgetting_factor,
                             float* dc_level,
                             rtc::ArrayView<float> x) {
   RTC_DCHECK(!x.empty());
   float mean =
-      std::accumulate(x.begin(), x.end(), 0) / static_cast<float>(x.size());
+      std::accumulate(x.begin(), x.end(), 0.0f) / static_cast<float>(x.size());
   *dc_level += forgetting_factor * (mean - *dc_level);
 
   for (float& v : x) {
     v -= *dc_level;
   }
 }
 
 float FrameEnergy(const AudioBuffer& audio) {
   float energy = 0.f;
   for (size_t k = 0; k < audio.num_channels(); ++k) {
@@ skipping 172 matching lines @@
   data_dumper_->DumpRaw("lc_selected_gain", 1, &last_gain_);
   data_dumper_->DumpRaw("lc_noise_energy", 1, &noise_energy);
   data_dumper_->DumpRaw("lc_peak_level", 1, &peak_level);
   data_dumper_->DumpRaw("lc_saturating_gain", 1, &saturating_gain);
 
   data_dumper_->DumpWav("lc_output", audio->num_frames(),
                         audio->channels_f()[0], *sample_rate_hz_, 1);
 }
 
 }  // namespace webrtc