Yes, Webkit is originally based on KDE's KHTML, and thus written in C++. It was heavily modified by Apple and later by Google. The core is platform independent C++, and then there are platform specific parts for the various environments it runs in (C/C++ for Gtk, C++ for Qt, ObjC for OSX, ...).
With the clang or gcc compilers, you can easily link ObjC and C++ together. To some extent you can even mix them in one file (ObjC++), though I don't have experience with that.
With the clang or gcc compilers, you can easily link ObjC and C++ together. To some extent you can even mix them in one file (ObjC++), though I don't have experience with that.