This seems to me a useful public interface to manage persistent storage for separate QWebPage's within one process. It is also used by some existing QtWebKit clients which could cause some problems as at the moment this is not a publicly supported API.
Laszlo, is this still needed for 2.1? If so, we're gonna need a patch real quick :)
https://lists.webkit.org/pipermail/webkit-dev/2013-October/025609.html