Otherwise it could stay client side without being submitted to the GL
server resulting in another context waiting on a Fence that will never
become signalled causing a deadlock.
A context can create a GLsync object that can be waited on in order
to ensure that GL resources created in one context are able to be
used in another shared context without any chance of reading invalid
data.
This meta would be placed on buffers that are known to cross from
one context to another. The receiving element would then wait
on the sync object to ensure that the data to be used is complete.
