Update audio code to use size_t more correctly, webrtc/common_audio/ portion.

webrtc/common_audio/window_generator.h

Index: webrtc/common_audio/window_generator.h
diff --git a/webrtc/common_audio/window_generator.h b/webrtc/common_audio/window_generator.h
index ee0acada5200d9b3933c5c09d72993e66ce14203..f28542c8f96d8f9cf41a35ec819114dfe27af8a2 100644
--- a/webrtc/common_audio/window_generator.h
+++ b/webrtc/common_audio/window_generator.h
@@ -11,6 +11,8 @@
 #ifndef WEBRTC_COMMON_AUDIO_WINDOW_GENERATOR_H_
 #define WEBRTC_COMMON_AUDIO_WINDOW_GENERATOR_H_
 
+#include <stddef.h>
+
 #include "webrtc/base/constructormagic.h"
 
 namespace webrtc {
@@ -19,7 +21,7 @@ namespace webrtc {
 class WindowGenerator {
  public:
   static void Hanning(int length, float* window);
-  static void KaiserBesselDerived(float alpha, int length, float* window);
+  static void KaiserBesselDerived(float alpha, size_t length, float* window);
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(WindowGenerator);