Convert channel counts to size_t.

webrtc/modules/audio_processing/high_pass_filter_impl.h

 /*
  *  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.
  */
 
 #ifndef WEBRTC_MODULES_AUDIO_PROCESSING_HIGH_PASS_FILTER_IMPL_H_
 #define WEBRTC_MODULES_AUDIO_PROCESSING_HIGH_PASS_FILTER_IMPL_H_
 
 #include "webrtc/base/constructormagic.h"
 #include "webrtc/base/criticalsection.h"
 #include "webrtc/base/scoped_ptr.h"
 #include "webrtc/modules/audio_processing/include/audio_processing.h"
 
 namespace webrtc {
 
 class AudioBuffer;
 
 class HighPassFilterImpl : public HighPassFilter {
  public:
   explicit HighPassFilterImpl(rtc::CriticalSection* crit);
   ~HighPassFilterImpl() override;
 
   // TODO(peah): Fold into ctor, once public API is removed.
-  void Initialize(int channels, int sample_rate_hz);
+  void Initialize(size_t channels, int sample_rate_hz);
   void ProcessCaptureAudio(AudioBuffer* audio);
 
   // HighPassFilter implementation.
   int Enable(bool enable) override;
   bool is_enabled() const override;
 
  private:
   class BiquadFilter;
   rtc::CriticalSection* const crit_ = nullptr;
   bool enabled_ GUARDED_BY(crit_) = false;
   std::vector<rtc::scoped_ptr<BiquadFilter>> filters_ GUARDED_BY(crit_);
   RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(HighPassFilterImpl);
 };
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_AUDIO_PROCESSING_HIGH_PASS_FILTER_IMPL_H_