Use interface mixins instead of [NoInterfaceObject]

[romandev]

WebIDL recently introduced dedicated syntax for mixins[1]. So, we can
replace [NoInterfaceObject] and implements with interface mixin and
includes.

Test: web-platform-tests/wpt#8703

[1] whatwg/webidl@45e8173

---

/acknowledgements.html ( diff )
/canvas.html ( diff )
/dom.html ( diff )
/image-maps.html ( diff )
/index.html ( diff )
/interaction.html ( diff )
/links.html ( diff )
/obsolete.html ( diff )
/offline.html ( diff )
/sections.html ( diff )
/semantics.html ( diff )
/system-state.html ( diff )
/text-level-semantics.html ( diff )
/urls-and-fetching.html ( diff )
/webappapis.html ( diff )
/webstorage.html ( diff )
/window-object.html ( diff )
/workers.html ( diff )

[romandev]

@tobie Could you check that this patch is going on the right direction?

[tobie]

It is. :) You can track your work here, if needed: #3194.

[annevk]

Thanks @romandev! We might also be able to reduce some [Exposed] usage as mixins inherit that from whatever they're included into (when it's more restrictive it'll have to stay).

As noted in the issue @tobie points to we might have to wait with landing this for a while until we know that all tooling is updated. Hope that's understandable.

[romandev]

@tobie, @annevk Thank you for your comments!

@annevk I'm first-time contributor, so, I didn't fully understand your context.
If you don't mind, could you let me know what kind of tools you mentioned?
(e.g. webidl2? or binding implementation such as Chromium binding?)

Thank you!

[annevk]

@romandev relevant here are https://github.com/plinss/widlparser and https://github.com/tabatkins/bikeshed I think. Those are used to scrape the HTML Standard and extract all the IDL fragments which are then put in a database so other specifications can link to them.

[annevk]

To be clear, that doesn't mean your continued work here is not valuable. It just means we have to wait a bit before applying the patch to master.

[annevk]

The main outstanding problem here is that we still need to update idlharness.js.

[annevk]

It seems that was already updated. @romandev do you want to add your name to the Acknowledgments section?

[tobie]

While the syntax parser used by idlharness was updated, idlharness itself wasn't yet (see web-platform-tests/wpt#8054). I don't think [NoInterfaceObject] interfaces were tested before, so I don't think this will make a huge difference, unless it actually breaks stuff and throws errors.

[annevk]

Okay, I just merged a couple things... But I think you're right that if it wasn't tested before this should essentially no-op. Would be good to get those tested as well of course.

[tobie]

Would be good to get those tested as well of course.

I concur.

[romandev]

@annevk, @tobie Thank you for review. BTW, Are you working on fixing idlharness.js? I'm also working on it now. If you are working on it, please let me know. I can stop the work :)

[annevk]

I'm not.

[tobie]

Neither am I. :)

[domenic]

Given that other specs are already merging these I think we should merge it for HTML too. Fixing idlharness.js will be necessary before we can properly merge corresponding WPT PRs, but that's separable.

I'll do a last pass-through to check and then merge.

[annevk]

Note that @romandev updated idlharness in web-platform-tests/wpt#8727 to make it equally functional to the old version. A new PR is still required to actually test mixin members though.