BUG=232
TEST=convert.exe -f 0 faces_640x480_P420.yuv face2_160x120_P420.yuv
R=changjun.yang@intel.com

Review URL: https://webrtc-codereview.appspot.com/1579005

git-svn-id: http://libyuv.googlecode.com/svn/trunk@709 16f28f9a-4ce2-e073-06de-1de4eb20be90