Multiprocess rendering in wayland - webkitgtk+

Hi, I am working on porting WebKitGTK+ to Wayland and we are having some difficulties figuring out the proper way to deal with the multiprocess architecture introduced with WebKit2. In WebKit2 we have two processes that are responsible for rendering the contents of a webpage. The WebProcess takes care of parsing HTML, identifying the various layers that are part of that HTML (that will be rendered separately) and the composition of all these layers to create the final view of the page. This composition stage is done with OpenGL. Once the composition is done, the other process (UIProcess) needs a way to access the results of the composition and paint them on the screen. In X11, this is achieved by having the WebProcess render the composition results to an offscreen XWindow and sharing the XWindow ID between the two processes. XComposite is used to redirect the XWindow to a pixmap. The pixmap is painted in the UIProcess. As far as we know, there is no API in Wayland to allow two different processes to share a surface, so we are not sure if the architecture I describe above is currently supported in Wayland. So I guess my questions are: - Is there a way to share a surface between two processes? - If not, is there a way to implement this architecture in Wayland as it is now? - Would it be possible/interesting to add surface sharing API to Wayland so that it supports this type of architectures naturally? We would really love to see WebKitGTK+ fully ported to Wayland and this is probably the major obstacle we have at the moment so we are really looking forward to seeing the options we have available to make this happen. Also, notice I am adding two colleagues of mine to the CC who are not subscribed to this list. If you reply, please remember to keep them in the loop. Iago