Force clip in fast/regions/autoheight-break-after-expected.html to match test
https://bugs.webkit.org/show_bug.cgi?id=112283

Reviewed by David Hyatt.

Regions always set a clip rect when rendering their contents. On Mountain Lion, the Ahem glyphs very slightly
visually overflow their bounds if there's no clip set. This sets a clip in the reference file so we get the same
rendering.

* fast/regions/autoheight-break-after-expected.html:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@145749 268f45cc-cd09-0410-ab3c-d52691b4dbfc