Code review comment for lp://staging/~vanvugt/mir/parenting-server-api

> I completely agree, and have worked to remove as much from the frontend as
> possible, over multiple iterations.
>
> The key problem is parent "ID" only exists in the frontend. And correlating
> that with a parent ptr in the frontend appears to be much cleaner than the
> alternative of duplicating ID information into the scene; BasicSurface (where
> it's meaningless, hence absent right now). Not only that but pushing all ID
> responsibility into the lower layer would also require additional lookup
> functionality get pushed down there. Very ugly. This is cleaner.

I agree that any mapping of ID to ptr belongs in frontend.

However, following Thomas's meeting it is clear that some rework is needed to fit the design philosophy as there will not be a (re)parenting request from the client for an existing surface. C.f.

    https://lists.ubuntu.com/archives/mir-devel/2014-November/000961.html