[NOT FOR REVIEW] Convert channel counts to size_t.

webrtc/modules/audio_processing/level_estimator_impl.cc

 /*
  *  Copyright (c) 2012 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 12 matching lines @@
       crit_(crit) {}
 
 LevelEstimatorImpl::~LevelEstimatorImpl() {}
 
 int LevelEstimatorImpl::ProcessStream(AudioBuffer* audio) {
   if (!is_component_enabled()) {
     return AudioProcessing::kNoError;
   }
 
   RMSLevel* rms_level = static_cast<RMSLevel*>(handle(0));
-  for (int i = 0; i < audio->num_channels(); ++i) {
+  for (size_t i = 0; i < audio->num_channels(); ++i) {
     rms_level->Process(audio->channels_const()[i],
                        audio->num_frames());
   }
 
   return AudioProcessing::kNoError;
 }
 
 int LevelEstimatorImpl::Enable(bool enable) {
   CriticalSectionScoped crit_scoped(crit_);
   return EnableComponent(enable);
@@ skipping 24 matching lines @@
 
 int LevelEstimatorImpl::InitializeHandle(void* handle) const {
   static_cast<RMSLevel*>(handle)->Reset();
   return AudioProcessing::kNoError;
 }
 
 int LevelEstimatorImpl::ConfigureHandle(void* /*handle*/) const {
   return AudioProcessing::kNoError;
 }
 
-int LevelEstimatorImpl::num_handles_required() const {
+size_t LevelEstimatorImpl::num_handles_required() const {
   return 1;
 }
 
 int LevelEstimatorImpl::GetHandleError(void* /*handle*/) const {
   return AudioProcessing::kUnspecifiedError;
 }
 
 }  // namespace webrtc