Add histogram coloring for xla clusters similarly to devices.

[r4nt]

No description provided.

[nfelt]

Thanks for the contribution!

One quick question, not being very familiar with XLA - is there an easy way to generate demo/test data we could use to test this functionality?

[nfelt]

It'd be nice to also deduplicate the code for the TPU compatibility logic below - it looks like it was essentially copy-pasted between the device color and TPU compat color cases previously, so now that you've factored it out it would ideally be factored out in all three places.

I think it should be pretty easy to adapt, but if you'd rather not bother that's fine and one of us can clean it up later.

[r4nt]

Done.

[r4nt]

• adapted the demo test data with XLA cluster and TPU op compatibility test cases
• fixed the demo app to support loading graphs, which makes my other patch unnecessary

[nfelt]

LGTM, thanks for making those extra changes!

Re: the other PR, yeah I'm not sure why the tf_graph_app index.html only shows the documentation view, I think this is one of the only places in TensorBoard that's used, perhaps for some historical reason. We could probably change it but if the demo works for you for now that's great.