Add scale color test place holder source BUG=401 TESTED=untested
Add scale color test place holder source
BUG=401
TESTED=untested

Review URL: https://webrtc-codereview.appspot.com/55539004

git-svn-id: a51711482b6ba0e1d1ab095578a045eeae45ac9a@1418 16f28f9a-4ce2-e073-06de-1de4eb20be90

rig-project/libyuv,rig-project/libyuv,rig-project/libyuv