Mark windows form control tests as NeedsManualRebaseline for skia roll

Once we roll skia to f73c237291bb1fc698f688d8a9b1cdd23838ed18 a bunch
of windows form tests needs to be rebaselines.

BUG=395043
R=bungeman@chromium.org

Review URL: https://codereview.chromium.org/414873003

git-svn-id: svn://svn.chromium.org/blink/trunk@178787 bbb929c8-8fbe-4397-9dbb-9b2b20218538