Intent to ship: window.event

[Masayuki Nakano]

Summary: Enable window.event which can access dispatching event from
everywhere.

Bug: https://bugzilla.mozilla.org/show_bug.cgi?id=218415

Link to standard: https://dom.spec.whatwg.org/#ref-for-dom-window-event

Platform coverage: All

Estimated or target release: 65

DevTools bug: (not sure)

Do other browser engines implement this?

(I think so, but I'm not sure because of not my fix.)

Enabling patch has been landed from:
https://bugzilla.mozilla.org/show_bug.cgi?id=1496288
because we need to manage those changes as a set.

This was disabled temporarily due to a lot of web apps assume that
window.event is available only in IE, and IE stores a Unicode code point
in keyCode of "keypress" event. Google Chrome and Edge followed same
behavior for both, so, such apps work even with them.

This is now fixed by the both fixes of:
https://groups.google.com/forum/#!topic/mozilla.dev.platform/E8DyIJBhu1g
https://groups.google.com/forum/#!topic/mozilla.dev.platform/IWLLJmoGroA

--
Masayuki Nakano <masa...@d-toybox.com>
Software Engineer, Mozilla

[Masayuki Nakano]

We've decided to put this off at least 66.
https://bugzilla.mozilla.org/show_bug.cgi?id=1520756