Unreviewed gardening; fix bindings tests after r148700.

* bindings/scripts/test/JS/JSTestEventTarget.cpp:
(WebCore::JSTestEventTargetOwner::isReachableFromOpaqueRoots):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@148714 268f45cc-cd09-0410-ab3c-d52691b4dbfc