Update a ton of audio code to use size_t more correctly and in general reduce

webrtc/common_audio/include/audio_util.h

Index: webrtc/common_audio/include/audio_util.h
diff --git a/webrtc/common_audio/include/audio_util.h b/webrtc/common_audio/include/audio_util.h
index 99771dd6003497b143bfad561b2ec1690eb3565a..d8e1ce378e4007b09dbbbacc7cdf0e5ae96e92fd 100644
--- a/webrtc/common_audio/include/audio_util.h
+++ b/webrtc/common_audio/include/audio_util.h
@@ -86,13 +86,13 @@ void CopyAudioIfNeeded(const T* const* src,
 // per buffer).
 template <typename T>
 void Deinterleave(const T* interleaved,
-                  int samples_per_channel,
+                  size_t samples_per_channel,
                   int num_channels,
                   T* const* deinterleaved) {
   for (int i = 0; i < num_channels; ++i) {
     T* channel = deinterleaved[i];
     int interleaved_idx = i;
-    for (int j = 0; j < samples_per_channel; ++j) {
+    for (size_t j = 0; j < samples_per_channel; ++j) {
       channel[j] = interleaved[interleaved_idx];
       interleaved_idx += num_channels;
     }
@@ -104,13 +104,13 @@ void Deinterleave(const T* interleaved,
 // (|samples_per_channel| * |num_channels|).
 template <typename T>
 void Interleave(const T* const* deinterleaved,
-                int samples_per_channel,
+                size_t samples_per_channel,
                 int num_channels,
                 T* interleaved) {
   for (int i = 0; i < num_channels; ++i) {
     const T* channel = deinterleaved[i];
     int interleaved_idx = i;
-    for (int j = 0; j < samples_per_channel; ++j) {
+    for (size_t j = 0; j < samples_per_channel; ++j) {
       interleaved[interleaved_idx] = channel[j];
       interleaved_idx += num_channels;
     }
@@ -135,10 +135,10 @@ void UpmixMonoToInterleaved(const T* mono,
 
 template <typename T, typename Intermediate>
 void DownmixToMono(const T* const* input_channels,
-                   int num_frames,
+                   size_t num_frames,
                    int num_channels,
                    T* out) {
-  for (int i = 0; i < num_frames; ++i) {
+  for (size_t i = 0; i < num_frames; ++i) {
     Intermediate value = input_channels[0][i];
     for (int j = 1; j < num_channels; ++j) {
       value += input_channels[j][i];
@@ -151,11 +151,11 @@ void DownmixToMono(const T* const* input_channels,
 // all channels.
 template <typename T, typename Intermediate>
 void DownmixInterleavedToMonoImpl(const T* interleaved,
-                                  int num_frames,
+                                  size_t num_frames,
                                   int num_channels,
                                   T* deinterleaved) {
   DCHECK_GT(num_channels, 0);
-  DCHECK_GT(num_frames, 0);
+  DCHECK_GT(num_frames, 0u);
 
   const T* const end = interleaved + num_frames * num_channels;
 
@@ -173,13 +173,13 @@ void DownmixInterleavedToMonoImpl(const T* interleaved,
 
 template <typename T>
 void DownmixInterleavedToMono(const T* interleaved,
-                              int num_frames,
+                              size_t num_frames,
                               int num_channels,
                               T* deinterleaved);
 
 template <>
 void DownmixInterleavedToMono<int16_t>(const int16_t* interleaved,
-                                       int num_frames,
+                                       size_t num_frames,
                                        int num_channels,
                                        int16_t* deinterleaved);