BUG=none
TESTED=local build on clang for osx
R=harryjin@google.com

Review URL: https://webrtc-codereview.appspot.com/30869004

git-svn-id: http://libyuv.googlecode.com/svn/trunk@1153 16f28f9a-4ce2-e073-06de-1de4eb20be90