This was broken by http://trac.webkit.org/changeset/59611
http://trac.webkit.org/changeset/59765
This should probably cherry-picked to qtwebkit-2.0, since https://bugs.webkit.org/show_bug.cgi?id=39218 was also picked.
<cherry-pick-for-backport: r59765>
Revision r59765 cherry-picked into qtwebkit-2.0 with commit d59845f6fec84f15da116f50a1a0e52ce26116e9