[RFD] Proposal for merging Android sync driver in staging

I'd like to get a discussion going about submitting the Android sync 
driver to staging.

I know there is currently some very similar work going on with the 
dmabuf-fences, and rather then both approaches being worked out 
individually on their own, I suspect there could be better collaboration 
around this effort.

So my proposal is that we merge the Android sync driver into staging.

In my mind, this has the following benefits:
1) It allows other drivers that depend on the sync interface to also be 
submitted to staging, rather then forcing those drivers to be hidden 
away in various out of tree git repos, location unknown.

2) It would provide a baseline view to the upstream community of the 
interface Android is using, providing  a real-world, active use case of 
the functionality.

Once the sync driver is in staging, if the dmabuf-fences work is fully 
sufficient to replace the Android sync driver, we should be able to 
whittle down the sync driver until its just a interface shim (and at 
which point efforts can be made to convert Android userland over to 
dmabuf-fences).

However, if the dmabuf-fences work is not fully sufficient to replace 
the android sync driver, we should be able to at least to whittle down 
the driver to those specific differences, which would provide a concrete 
example of where the dmabuf-fences, or other work may need to be 
expanded, or if maybe the sync driver is the better approach.