Gardening: Mark two failing virtual/threaded/animations tests as failing

BUG=369330
TBR=falken@chromium.org

Review URL: https://codereview.chromium.org/269573009

git-svn-id: svn://svn.chromium.org/blink/trunk@173133 bbb929c8-8fbe-4397-9dbb-9b2b20218538