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

webrtc/modules/audio_coding/codecs/pcm16b/include/pcm16b.h

Index: webrtc/modules/audio_coding/codecs/pcm16b/include/pcm16b.h
diff --git a/webrtc/modules/audio_coding/codecs/pcm16b/include/pcm16b.h b/webrtc/modules/audio_coding/codecs/pcm16b/include/pcm16b.h
index 1cdf92dbf8fc4f2ad0c0382c9ef3520e900f880c..d65d08af1a6bd1c31b5f9f8ad7a6b2fb4580c131 100644
--- a/webrtc/modules/audio_coding/codecs/pcm16b/include/pcm16b.h
+++ b/webrtc/modules/audio_coding/codecs/pcm16b/include/pcm16b.h
@@ -14,6 +14,8 @@
  * Define the fixpoint numeric formats
  */
 
+#include <stddef.h>
+
 #include "webrtc/typedefs.h"
 
 #ifdef __cplusplus
@@ -36,9 +38,9 @@ extern "C" {
  *                                Always equal to twice the len input parameter.
  */
 
-int16_t WebRtcPcm16b_Encode(const int16_t* speech,
-                            int16_t len,
-                            uint8_t* encoded);
+size_t WebRtcPcm16b_Encode(const int16_t* speech,
+                           size_t len,
+                           uint8_t* encoded);
 
 /****************************************************************************
  * WebRtcPcm16b_Decode(...)
@@ -55,9 +57,9 @@ int16_t WebRtcPcm16b_Encode(const int16_t* speech,
  * Returned value               : Samples in speech
  */
 
-int16_t WebRtcPcm16b_Decode(const uint8_t* encoded,
-                            int16_t len,
-                            int16_t* speech);
+size_t WebRtcPcm16b_Decode(const uint8_t* encoded,
+                           size_t len,
+                           int16_t* speech);
 
 #ifdef __cplusplus
 }