[NOT FOR REVIEW] Convert channel counts to size_t.

webrtc/modules/audio_processing/test/audioproc_float.cc

Index: webrtc/modules/audio_processing/test/audioproc_float.cc
diff --git a/webrtc/modules/audio_processing/test/audioproc_float.cc b/webrtc/modules/audio_processing/test/audioproc_float.cc
index d2983b2c56d2f6d99e21449f90a0ad70dd949f4f..9da4e7574c3277e9b007bcc8832e259d99b0384e 100644
--- a/webrtc/modules/audio_processing/test/audioproc_float.cc
+++ b/webrtc/modules/audio_processing/test/audioproc_float.cc
@@ -14,6 +14,7 @@
 
 #include "gflags/gflags.h"
 #include "webrtc/base/checks.h"
+#include "webrtc/base/format_macros.h"
 #include "webrtc/base/scoped_ptr.h"
 #include "webrtc/common_audio/channel_buffer.h"
 #include "webrtc/common_audio/wav_file.h"
@@ -23,10 +24,20 @@
 #include "webrtc/system_wrappers/interface/tick_util.h"
 #include "webrtc/test/testsupport/trace_to_stderr.h"
 
+namespace {
+
+bool ValidateOutChannels(const char* flagname, int32_t value) {
+  return value >= 0;
+}
+
+}  // namespace
+
 DEFINE_string(dump, "", "The name of the debug dump file to read from.");
 DEFINE_string(i, "", "The name of the input file to read from.");
 DEFINE_string(o, "out.wav", "Name of the output file to write to.");
 DEFINE_int32(out_channels, 0, "Number of output channels. Defaults to input.");
+const bool out_channels_dummy =
+    google::RegisterFlagValidator(&FLAGS_out_channels, &ValidateOutChannels);
 DEFINE_int32(out_sample_rate, 0,
              "Output sample rate in Hz. Defaults to input.");
 DEFINE_string(mic_positions, "",
@@ -77,8 +88,8 @@ int main(int argc, char* argv[]) {
   test::TraceToStderr trace_to_stderr(true);
   WavReader in_file(FLAGS_i);
   // If the output format is uninitialized, use the input format.
-  const int out_channels =
-      FLAGS_out_channels ? FLAGS_out_channels : in_file.num_channels();
+  const size_t out_channels = FLAGS_out_channels ?
+      static_cast<size_t>(FLAGS_out_channels) : in_file.num_channels();
   const int out_sample_rate =
       FLAGS_out_sample_rate ? FLAGS_out_sample_rate : in_file.sample_rate();
   WavWriter out_file(FLAGS_o, out_sample_rate, out_channels);
@@ -110,9 +121,9 @@ int main(int argc, char* argv[]) {
     CHECK_EQ(kNoErr, ap->noise_suppression()->set_level(
         static_cast<NoiseSuppression::Level>(FLAGS_ns_level)));
 
-  printf("Input file: %s\nChannels: %d, Sample rate: %d Hz\n\n",
+  printf("Input file: %s\nChannels: %" PRIuS ", Sample rate: %d Hz\n\n",
          FLAGS_i.c_str(), in_file.num_channels(), in_file.sample_rate());
-  printf("Output file: %s\nChannels: %d, Sample rate: %d Hz\n\n",
+  printf("Output file: %s\nChannels: %" PRIuS ", Sample rate: %d Hz\n\n",
          FLAGS_o.c_str(), out_file.num_channels(), out_file.sample_rate());
 
   ChannelBuffer<float> in_buf(