Convert channel counts to size_t.

webrtc/modules/audio_coding/test/EncodeDecodeTest.h

Index: webrtc/modules/audio_coding/test/EncodeDecodeTest.h
diff --git a/webrtc/modules/audio_coding/test/EncodeDecodeTest.h b/webrtc/modules/audio_coding/test/EncodeDecodeTest.h
index 3881062219328369371e57f0dcd3f737fac0eb71..f9a9a5bb520c446d8c21f2a5ccb38994be46a8f9 100644
--- a/webrtc/modules/audio_coding/test/EncodeDecodeTest.h
+++ b/webrtc/modules/audio_coding/test/EncodeDecodeTest.h
@@ -48,7 +48,7 @@ class Sender {
  public:
   Sender();
   void Setup(AudioCodingModule *acm, RTPStream *rtpStream,
-             std::string in_file_name, int sample_rate, int channels);
+             std::string in_file_name, int sample_rate, size_t channels);
   void Teardown();
   void Run();
   bool Add10MsData();
@@ -71,7 +71,7 @@ class Receiver {
   Receiver();
   virtual ~Receiver() {};
   void Setup(AudioCodingModule *acm, RTPStream *rtpStream,
-             std::string out_file_name, int channels);
+             std::string out_file_name, size_t channels);
   void Teardown();
   void Run();
   virtual bool IncomingPacket();