scaling from 1x1 will cause dx/dy to be 0.  This was confusing the specialized scalers into calling the wrong function.
BUG=none
TEST=none
R=johannkoenig@google.com, noahric@chromium.org

Review URL: https://webrtc-codereview.appspot.com/1591004

git-svn-id: http://libyuv.googlecode.com/svn/trunk@713 16f28f9a-4ce2-e073-06de-1de4eb20be90
3 files changed