[dom] Define event path computation (#165)

The way this works I think is that an object that implements EventTarget can optionally implement an "event path computation" algorithm that returns a list of objects that all implement EventTarget. The dispatch algorithm then uses that.

This should allow for what we do with nodes and should allow @inexorabletash to use it for IDB.

This can then serve as a basis for what Shadow DOM needs to modify.

We should also inline this monkey patch from HTML: https://html.spec.whatwg.org/multipage/webappapis.html#events-and-the-window-object.

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Reply to this email directly or view it on GitHub:
https://github.com/whatwg/dom/issues/165