Add an image only failure expectation to fast/css-generated-content/close-quote-negative-depth.html per
bug 115776 after r149700. r149707 tried to fix its regression but this test is still failing.

* TestExpectations:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@149715 268f45cc-cd09-0410-ab3c-d52691b4dbfc