Port I422ToBGRA from Windows version that does 16 pixels at a time, for performance improvement.

BUG=386
TESTED=nacl build
R=brucedawson@google.com, harryjin@google.com

Review URL: https://webrtc-codereview.appspot.com/36549004

git-svn-id: http://libyuv.googlecode.com/svn/trunk@1207 16f28f9a-4ce2-e073-06de-1de4eb20be90

README.chromium

 Name: libyuv
 URL: http://code.google.com/p/libyuv/
-Version: 1206
+Version: 1207
 License: BSD
 License File: LICENSE
 

include/libyuv/version.h

@@ -11,6 +11,6 @@
 #ifndef INCLUDE_LIBYUV_VERSION_H_  // NOLINT
 #define INCLUDE_LIBYUV_VERSION_H_
 
-#define LIBYUV_VERSION 1206
+#define LIBYUV_VERSION 1207
 
 #endif  // INCLUDE_LIBYUV_VERSION_H_  NOLINT