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

webrtc/common_audio/audio_util.cc

Index: webrtc/common_audio/audio_util.cc
diff --git a/webrtc/common_audio/audio_util.cc b/webrtc/common_audio/audio_util.cc
index b330b944f17f5eefd5385588f4e8aee7f7e0041a..2ce2eba994f288010675bb912b02772dc09158cb 100644
--- a/webrtc/common_audio/audio_util.cc
+++ b/webrtc/common_audio/audio_util.cc
@@ -41,7 +41,7 @@ void FloatS16ToFloat(const float* src, size_t size, float* dest) {
 
 template <>
 void DownmixInterleavedToMono<int16_t>(const int16_t* interleaved,
-                                       int num_frames,
+                                       size_t num_frames,
                                        int num_channels,
                                        int16_t* deinterleaved) {
   DownmixInterleavedToMonoImpl<int16_t, int32_t>(interleaved, num_frames,