Support for off-screen rending through SetAsOffScreen.
It is available for Mac OS X and Windows, but unfortunately not Linux. Essentially I would imagine it would mean replicating most of what has been done to the Mac OS X version. The problem is that the corresponding commit (http://code.google.com/p/chromiumembedd ... ail?r=625#) includes various other things, so it's not that easy to figure out exactly what would be needed for someone who doesn't know the codebase well. But if magrennblatt could say something about what of this relates to off-screen rendering and how the Linux version is different in a way that made it impossible to copy the Mac OS X code, then that would be helpful and I could have a go at it.
This has previously been mentioned as a "bug": http://code.google.com/p/chromiumembedd ... rt=&id=594