[NOT FOR REVIEW] Convert channel counts to size_t.

webrtc/common_audio/wav_file.cc

Index: webrtc/common_audio/wav_file.cc
diff --git a/webrtc/common_audio/wav_file.cc b/webrtc/common_audio/wav_file.cc
index a0c792c54a6fab246dd66afca5af860cdb53a7f8..94b834a6ac8fc6ecd1b70ddf7ad4d7e9e5f5a92a 100644
--- a/webrtc/common_audio/wav_file.cc
+++ b/webrtc/common_audio/wav_file.cc
@@ -23,7 +23,7 @@ namespace webrtc {
 
 // We write 16-bit PCM WAV files.
 static const WavFormat kWavFormat = kWavFormatPcm;
-static const int kBytesPerSample = 2;
+static const size_t kBytesPerSample = 2;
 
 // Doesn't take ownership of the file handle and won't close it.
 class ReadableWavFile : public ReadableWav {
@@ -43,7 +43,7 @@ WavReader::WavReader(const std::string& filename)
 
   ReadableWavFile readable(file_handle_);
   WavFormat format;
-  int bytes_per_sample;
+  size_t bytes_per_sample;
   CHECK(ReadWavHeader(&readable, &num_channels_, &sample_rate_, &format,
                       &bytes_per_sample, &num_samples_));
   num_samples_remaining_ = num_samples_;
@@ -60,14 +60,13 @@ size_t WavReader::ReadSamples(size_t num_samples, int16_t* samples) {
 #error "Need to convert samples to big-endian when reading from WAV file"
 #endif
   // There could be metadata after the audio; ensure we don't read it.
-  num_samples = std::min(rtc::checked_cast<uint32_t>(num_samples),
-                         num_samples_remaining_);
+  num_samples = std::min(num_samples, num_samples_remaining_);
   const size_t read =
       fread(samples, sizeof(*samples), num_samples, file_handle_);
   // If we didn't read what was requested, ensure we've reached the EOF.
   CHECK(read == num_samples || feof(file_handle_));
   CHECK_LE(read, num_samples_remaining_);
-  num_samples_remaining_ -= rtc::checked_cast<uint32_t>(read);
+  num_samples_remaining_ -= read;
   return read;
 }
 
@@ -91,7 +90,7 @@ void WavReader::Close() {
 }
 
 WavWriter::WavWriter(const std::string& filename, int sample_rate,
-                     int num_channels)
+                     size_t num_channels)
     : sample_rate_(sample_rate),
       num_channels_(num_channels),
       num_samples_(0),
@@ -120,9 +119,8 @@ void WavWriter::WriteSamples(const int16_t* samples, size_t num_samples) {
   const size_t written =
       fwrite(samples, sizeof(*samples), num_samples, file_handle_);
   CHECK_EQ(num_samples, written);
-  num_samples_ += static_cast<uint32_t>(written);
-  CHECK(written <= std::numeric_limits<uint32_t>::max() ||
-        num_samples_ >= written);  // detect uint32_t overflow
+  num_samples_ += written;
+  CHECK(num_samples_ >= written);  // detect size_t overflow
 }
 
 void WavWriter::WriteSamples(const float* samples, size_t num_samples) {
@@ -149,7 +147,7 @@ void WavWriter::Close() {
 
 rtc_WavWriter* rtc_WavOpen(const char* filename,
                            int sample_rate,
-                           int num_channels) {
+                           size_t num_channels) {
   return reinterpret_cast<rtc_WavWriter*>(
       new webrtc::WavWriter(filename, sample_rate, num_channels));
 }
@@ -168,7 +166,7 @@ int rtc_WavSampleRate(const rtc_WavWriter* wf) {
   return reinterpret_cast<const webrtc::WavWriter*>(wf)->sample_rate();
 }
 
-int rtc_WavNumChannels(const rtc_WavWriter* wf) {
+size_t rtc_WavNumChannels(const rtc_WavWriter* wf) {
   return reinterpret_cast<const webrtc::WavWriter*>(wf)->num_channels();
 }