Add more rebaselines for just enabled virtual/softwarecompositing tests on Mac

TBR=ojan,danakj@chromium.org,ccameron,enne
BUG=235110

Review URL: https://codereview.chromium.org/301513002

git-svn-id: svn://svn.chromium.org/blink/trunk@174768 bbb929c8-8fbe-4397-9dbb-9b2b20218538