The API QWebScriptWorld has been introduced in June, before the branching of 2.1. This API is exported, without any documentation, and has never been part of the API reviews.
This class seems to be a work in progress, it should _not_ be in the 2.1 release.
I'm working on it.
Fixed on QtWebKit branch with the following commits:
(reverts of the original patches)
(update of symbian .def files)