BUG=357
TESTED=local ios a64 build
R=yunqingwang@google.com

Review URL: https://webrtc-codereview.appspot.com/25549004

git-svn-id: http://libyuv.googlecode.com/svn/trunk@1084 16f28f9a-4ce2-e073-06de-1de4eb20be90