Update audio code to use size_t more correctly, webrtc/voice_engine/ portion.

webrtc/voice_engine/test/auto_test/standard/external_media_test.cc

 /*
  *  Copyright (c) 2012 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 65 matching lines @@
 }
 
 TEST_F(ExternalMediaTest,
        ExternalMixingWorks) {
   webrtc::AudioFrame frame;
   PausePlaying();
   EXPECT_EQ(0, voe_xmedia_->SetExternalMixing(channel_, true));
   ResumePlaying();
   EXPECT_EQ(0, voe_xmedia_->GetAudioFrame(channel_, 0, &frame));
   EXPECT_GT(frame.sample_rate_hz_, 0);
-  EXPECT_GT(frame.samples_per_channel_, 0);
+  EXPECT_GT(frame.samples_per_channel_, 0U);
   PausePlaying();
   EXPECT_EQ(0, voe_xmedia_->SetExternalMixing(channel_, false));
   ResumePlaying();
 }
 
 TEST_F(ExternalMediaTest,
        ExternalMixingResamplesToDesiredFrequency) {
   const int kValidFrequencies[] = {8000, 16000, 22000, 32000, 48000};
   webrtc::AudioFrame frame;
   PausePlaying();
   EXPECT_EQ(0, voe_xmedia_->SetExternalMixing(channel_, true));
   ResumePlaying();
   for (size_t i = 0; i < arraysize(kValidFrequencies); i++) {
     int f = kValidFrequencies[i];
     EXPECT_EQ(0, voe_xmedia_->GetAudioFrame(channel_, f, &frame))
        << "Resampling succeeds for freq=" << f;
     EXPECT_EQ(f, frame.sample_rate_hz_);
-    EXPECT_EQ(f / 100, frame.samples_per_channel_);
+    EXPECT_EQ(static_cast<size_t>(f / 100), frame.samples_per_channel_);
   }
   PausePlaying();
   EXPECT_EQ(0, voe_xmedia_->SetExternalMixing(channel_, false));
   ResumePlaying();
 }
 
 TEST_F(ExternalMediaTest,
        ExternalMixingResamplingToInvalidFrequenciesFails) {
   const int kInvalidFrequencies[] = {-8000, -1};
   webrtc::AudioFrame frame;
   PausePlaying();
   EXPECT_EQ(0, voe_xmedia_->SetExternalMixing(channel_, true));
   ResumePlaying();
   for (size_t i = 0; i < arraysize(kInvalidFrequencies); i++) {
     int f = kInvalidFrequencies[i];
     EXPECT_EQ(-1, voe_xmedia_->GetAudioFrame(channel_, f, &frame))
         << "Resampling fails for freq=" << f;
   }
   PausePlaying();
   EXPECT_EQ(0, voe_xmedia_->SetExternalMixing(channel_, false));
   ResumePlaying();
 }