Convert channel counts to size_t.

webrtc/modules/audio_processing/noise_suppression_impl.h

Index: webrtc/modules/audio_processing/noise_suppression_impl.h
diff --git a/webrtc/modules/audio_processing/noise_suppression_impl.h b/webrtc/modules/audio_processing/noise_suppression_impl.h
index 491c4d2c3254b7a00a1c8dc10b54e49515c82a8d..debbc61bc95c4b724b2e73c37c95b3e6799c34c3 100644
--- a/webrtc/modules/audio_processing/noise_suppression_impl.h
+++ b/webrtc/modules/audio_processing/noise_suppression_impl.h
@@ -26,7 +26,7 @@ class NoiseSuppressionImpl : public NoiseSuppression {
   ~NoiseSuppressionImpl() 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 AnalyzeCaptureAudio(AudioBuffer* audio);
   void ProcessCaptureAudio(AudioBuffer* audio);
 
@@ -42,7 +42,7 @@ class NoiseSuppressionImpl : public NoiseSuppression {
   rtc::CriticalSection* const crit_;
   bool enabled_ GUARDED_BY(crit_) = false;
   Level level_ GUARDED_BY(crit_) = kModerate;
-  int channels_ GUARDED_BY(crit_) = 0;
+  size_t channels_ GUARDED_BY(crit_) = 0;
   int sample_rate_hz_ GUARDED_BY(crit_) = 0;
   std::vector<rtc::scoped_ptr<Suppressor>> suppressors_ GUARDED_BY(crit_);
   RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(NoiseSuppressionImpl);