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: bf5a3199f700ba6c6bc955061af37b17b9b2ab23 http://gitorious.org/webkit/qtwebkit/commit/bf5a319 f329fc4bdf7064c9bda53e2d24570c5ff0d5d3bb http://gitorious.org/webkit/qtwebkit/commit/f329fc4 d625977d3258517c0472fdc8e83b770423ab1a62 http://gitorious.org/webkit/qtwebkit/commit/d625977 (reverts of the original patches) 9f5739175e12af51db38acb7f47d2aec76b56599 http://gitorious.org/webkit/qtwebkit/commit/9f57391 (update of symbian .def files)