Need to define where the EventHandler type comes from

[beverloo]

We refer to the EventHandler type in the Events section, which is defined in HTML.

Currently we depend on HTML 5.1 for such definitions, however, it does not export the EventHandler type. Instead, it links through to the WHATWG version of the specification, despite defining what it means.

https://www.w3.org/TR/html51/webappapis.html#dom-eventhandlernonnull-event

Is this an oversight? Should we depend on the WHATWG version directly for this type?

[marcoscaceres]

We depend on WHATWG for all underlying web platform stuff now... closing.