While working on module script, I'd like to use Promise with a custom
callback with type `Box<dyn TaskBox>` which means we didn't use web API
callbacks as native handlers. However, we'll get a panic from
`enqueue_promise_job` and the panic says we have a `null` incumbent
global. The main problem here is, the Promise API is strongly tied to JS
engine and it always assumes there's a meaningful answer for "what
specific global is this promise associated with". So, when I don't use
the Promise for a specific web API, our engine cannot find a proper
incumbent global for us so that we get the `null` incumbent global
panic.
To make us catch this case easier in the future, we should add the
assertion inside `get_incumbent_global` hook so that we can know this
quickly next time.
Ref: https://mozilla.logbot.info/servo/20190807#c16525481
Update cmake
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Webxr magicleap
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Adds the magicleap back end for webxr.
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Remove most of the things in layout 2020
We keep mostly the query system. There is probably more to delete but
that's a good start I think.
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Do not start up webvr services when running webxr and vice versa
Once we move everything over to the webxr crate we can relax the restriction around running both webxr and webvr
r? @asajeffrey
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