The solutions I have found are irrelevant:
I need a guide how to embed WebKit instance into a pure C/C++ application under Win32.
Brent Fulgham has put lots of work into producing a Windows Cairo port of WebKit, which doesn't rely on Apple's proprietary backend stuff (e.g. CoreGraphics, CoreFoundation, CFNetwork). I believe that is what you are after. The details aren't entirely collated in one place, but there is some information in the Trac wiki and other bits are dotted around on Brent's blog.