[uievents] Clarify what events are expected from <option> elements in <select> dropdowns (#55)

The specs for [the **option** element](https://html.spec.whatwg.org/multipage/forms.html#the-option-element) and [the **select** element](https://html.spec.whatwg.org/multipage/forms.html#the-select-element) do not (at least to my reading) make it clear what events are expected from **option** elements when the **select** is in dropdown mode (for example, when the <select> is not being used for multiple selections, or when the size of the <select> is 1).

I'm particularly interested in mouse and keyboard events.

The major browsers seem to behave differently. [I've highlighted those differences here](https://bugzilla.mozilla.org/show_bug.cgi?id=1090602#c27).

It'd be good if we could hammer out the actual desired behaviour here so that there's less ambiguity in how (if ever) to dispatch events for **option** elements when in dropdown **select**s.

[I wasn't sure where to file this, so I've cross-filed it here as well.](https://github.com/whatwg/html/issues/263)

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Reply to this email directly or view it on GitHub:
https://github.com/w3c/uievents/issues/55