[selection-api] Event handlers missing (#60)

Gecko implemented Document.onselectionchange and GlobalEventHandlers.onselectstart. [1]
Edge does it too (but both on Document [2])
Blink does it too (on both Document too [3])

These event handlers properties should be added to the spec.

[1] https://bugzilla.mozilla.org/show_bug.cgi?id=571294
[2] https://dev.modern.ie/platform/documentation/apireference/interfaces/document/
[3] https://chromium.googlesource.com/chromium/blink/+/master/Source/core/dom/Document.idl

---
Reply to this email directly or view it on GitHub:
https://github.com/w3c/selection-api/issues/60