[DOM] ParentNode.replaceChildren, Fx 78

[Elchi3]

Story

As a web developer, I want to know how about the latest DOM method ParentNode.replaceChildren that is now implemented in browsers.

Context why it is cool: whatwg/dom#478
Intent to ship https://groups.google.com/forum/#!topic/mozilla.dev.platform/eZ-UZT6rT5g

Acceptance criteria

The following bugs are dev-doc-complete, BCD is updated, an entry to Firefox release notes is added, experimental features page is updated if needed, and the content has been reviewed as needed.

1. • Implement ParentNode#replaceChildren

[Elchi3]

@chrisdavidmills please estimate. This landed overnight, but looks like it is still in for Firefox 78.

[chrisdavidmills]

This is a pretty simple method. I reckon 0.5 days at the most.

Note to self - would need to add it as a child page of https://developer.mozilla.org/en-US/docs/Web/API/ParentNode

[chrisdavidmills]

Ok, documentation done:

• Entry added to the methods list on the ParentNode page: https://wiki.developer.mozilla.org/en-US/docs/Web/API/ParentNode
• New page for replaceChildren() added: https://wiki.developer.mozilla.org/en-US/docs/Web/API/ParentNode/replaceChildren
• Rel note added: https://wiki.developer.mozilla.org/en-US/docs/Mozilla/Firefox/Releases/78#APIs
• BCD PR filed: adding in compat data for ParentNode querySelector and replaceChildren browser-compat-data#6234

In a moment, I'll set the bug to DDC.

[Elchi3]

Thanks Chris!