This is potentially a meta bug. Work needs to be done to make WebKit 2 work on Windows with Qt 5.
Making good progress on this one, got a prototype running with TextureMapperGL and Angle. That's going to get us bug #90879 fixed on the way :)
All patches are upstreamed, so I'm going to land the last patch to enable it in the build now. Additional fixes will be needed to stabilize the code base further, to iron out some bugs. But it basically works and leads me to closing this bug then :)
Committed r128466: <http://trac.webkit.org/changeset/128466>