Convert channel counts to size_t.

webrtc/modules/audio_coding/neteq/tools/neteq_external_decoder_test.cc

Index: webrtc/modules/audio_coding/neteq/tools/neteq_external_decoder_test.cc
diff --git a/webrtc/modules/audio_coding/neteq/tools/neteq_external_decoder_test.cc b/webrtc/modules/audio_coding/neteq/tools/neteq_external_decoder_test.cc
index 6becb86ccc2339a1a842c4191cb0b273baf0bffe..694b9ed15312fa1b93e72006ca4f9dddfbc39055 100644
--- a/webrtc/modules/audio_coding/neteq/tools/neteq_external_decoder_test.cc
+++ b/webrtc/modules/audio_coding/neteq/tools/neteq_external_decoder_test.cc
@@ -12,6 +12,7 @@
 #include "webrtc/modules/audio_coding/neteq/tools/neteq_external_decoder_test.h"
 
 #include "testing/gtest/include/gtest/gtest.h"
+#include "webrtc/base/format_macros.h"
 
 namespace webrtc {
 namespace test {
@@ -21,11 +22,11 @@ NetEqExternalDecoderTest::NetEqExternalDecoderTest(NetEqDecoder codec,
     : codec_(codec),
       decoder_(decoder),
       sample_rate_hz_(CodecSampleRateHz(codec_)),
-      channels_(static_cast<int>(decoder_->Channels())) {
+      channels_(decoder_->Channels()) {
   NetEq::Config config;
   config.sample_rate_hz = sample_rate_hz_;
   neteq_.reset(NetEq::Create(config));
-  printf("%d\n", channels_);
+  printf("%" PRIuS "\n", channels_);
 }
 
 void NetEqExternalDecoderTest::Init() {
@@ -47,7 +48,7 @@ size_t NetEqExternalDecoderTest::GetOutputAudio(size_t max_length,
                                                 NetEqOutputType* output_type) {
   // Get audio from regular instance.
   size_t samples_per_channel;
-  int num_channels;
+  size_t num_channels;
   EXPECT_EQ(NetEq::kOK,
             neteq_->GetAudio(max_length,
                              output,