[NOT FOR REVIEW] Convert channel counts to size_t.

webrtc/modules/audio_coding/neteq/neteq_external_decoder_unittest.cc

 /*
  *  Copyright (c) 2013 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.
  */
 
@@ skipping 171 matching lines @@
 
   void SetUp() override {
     ASSERT_EQ(NetEq::kOK,
               neteq_internal_->RegisterPayloadType(kDecoderPCM16Bswb32kHz,
                                                    kPayloadType));
   }
 
   void GetAndVerifyOutput() override {
     NetEqOutputType output_type;
     size_t samples_per_channel;
-    int num_channels;
+    size_t num_channels;
     // Get audio from internal decoder instance.
     EXPECT_EQ(NetEq::kOK,
               neteq_internal_->GetAudio(kMaxBlockSize,
                                         output_internal_,
                                         &samples_per_channel,
                                         &num_channels,
                                         &output_type));
-    EXPECT_EQ(1, num_channels);
+    EXPECT_EQ(1u, num_channels);
     EXPECT_EQ(static_cast<size_t>(kOutputLengthMs * sample_rate_hz_ / 1000),
               samples_per_channel);
 
     // Get audio from external decoder instance.
     samples_per_channel = GetOutputAudio(kMaxBlockSize, output_, &output_type);
 
     for (size_t i = 0; i < samples_per_channel; ++i) {
       ASSERT_EQ(output_[i], output_internal_[i]) <<
           "Diff in sample " << i << ".";
     }
@@ skipping 243 matching lines @@
                                                         kStartSeqeunceNumber,
                                                         kStartTimestamp,
                                                         kJumpFromTimestamp,
                                                         kJumpToTimestamp));
 
   RunTest(130);  // Run 130 laps @ 10 ms each in the test loop.
   EXPECT_EQ(kRecovered, test_state_);
 }
 
 }  // namespace webrtc