Remove TestExpectations for a test that has not crashed recently

There have not been any crashes recorded recently:
http://test-results.appspot.com/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=http%2Ftests%2Fsecurity%2FcontentSecurityPolicy%2Freport-only-from-header.php

There has been a timeout on WebKit Win Oilpan, so leave that alone.

BUG=282081
NOTRY=true

Review URL: https://codereview.chromium.org/528273002

git-svn-id: svn://svn.chromium.org/blink/trunk@181308 bbb929c8-8fbe-4397-9dbb-9b2b20218538