Convert channel counts to size_t.

webrtc/modules/audio_device/audio_device_buffer.h

Index: webrtc/modules/audio_device/audio_device_buffer.h
diff --git a/webrtc/modules/audio_device/audio_device_buffer.h b/webrtc/modules/audio_device/audio_device_buffer.h
index 2ab7ff55472dc5fce5ae0b38b15ecd456102ece7..1095971040d37e41afc846f079c28977bcf39cd3 100644
--- a/webrtc/modules/audio_device/audio_device_buffer.h
+++ b/webrtc/modules/audio_device/audio_device_buffer.h
@@ -40,10 +40,10 @@ public:
     int32_t RecordingSampleRate() const;
     int32_t PlayoutSampleRate() const;
 
-    virtual int32_t SetRecordingChannels(uint8_t channels);
-    virtual int32_t SetPlayoutChannels(uint8_t channels);
-    uint8_t RecordingChannels() const;
-    uint8_t PlayoutChannels() const;
+    virtual int32_t SetRecordingChannels(size_t channels);
+    virtual int32_t SetPlayoutChannels(size_t channels);
+    size_t RecordingChannels() const;
+    size_t PlayoutChannels() const;
     int32_t SetRecordingChannel(
         const AudioDeviceModule::ChannelType channel);
     int32_t RecordingChannel(
@@ -80,8 +80,8 @@ private:
     uint32_t                  _recSampleRate;
     uint32_t                  _playSampleRate;
 
-    uint8_t                   _recChannels;
-    uint8_t                   _playChannels;
+    size_t                   _recChannels;
+    size_t                   _playChannels;
 
     // selected recording channel (left/right/both)
     AudioDeviceModule::ChannelType _recChannel;