Fix segments-from-data-url.js to log PASS instead of just updating expected FAIL lines.

R=cbiesinger@chromium.org
BUG=346132

Review URL: https://codereview.chromium.org/184223007

git-svn-id: svn://svn.chromium.org/blink/trunk@168549 bbb929c8-8fbe-4397-9dbb-9b2b20218538