Makr some software compositing layout tests as failure

BUG=280213
TEST=none
TBR=haraken@chromium.org

Review URL: https://codereview.chromium.org/23572005

git-svn-id: svn://svn.chromium.org/blink/trunk@156788 bbb929c8-8fbe-4397-9dbb-9b2b20218538