There have been a few people who are interested in getting a build of a recent version of CEF with support for transparent backgrounds with the offscreen rendering. I have finally gotten to putting it together and you can download a modified version of CEF release 283 here.

After updating the Chromium code I found that my hackish modification that I had used before would no longer work, so I had to spend some time digging again to get things working the way I want. I ended up inserting some code in to the FrameView painting process to check if the FrameView is transparent and if so I flag the GraphicsContext so that it will use the appropriate text rendering path. I am still poking around the Chromium codebase some in order to better understand all the different parts and if there might be a better way to do this.

Whenever I end up needing to re-build the Chromium code on my poor little laptop I end up poking around and seeing what other solutions are out there. In my searching I came across this little project that is making use of the EAWebKit code. It seems like there would be interest for an EAWebKit like project - an open source project focused on providing a lightweight, windowless WebKit based browser for use in games, but I haven't really seen anything else springing from it. Maybe I've just missed it?