BUG=302
TESTED=ARGBScaleClipTo320x240_None etc
R=tpsiaki@google.com

Review URL: https://webrtc-codereview.appspot.com/6539004

git-svn-id: http://libyuv.googlecode.com/svn/trunk@946 16f28f9a-4ce2-e073-06de-1de4eb20be90