Expect media/track/css-cue-for-video-in-shadow-2 to pass

This test no longer shows any timeouts on flakiness dashboard.

BUG=282087
TBR=tasak@chromium.org,ojan@chromium.org

Review URL: https://codereview.chromium.org/110853014

git-svn-id: svn://svn.chromium.org/blink/trunk@164206 bbb929c8-8fbe-4397-9dbb-9b2b20218538