Bug#872923: Accessible state-changed event should be emitted in association with user agent validation

[Raphaël POITEVIN]

Package: firefox

Version: 55.0-2
Tags: a11y upstream
Severity: wishlist
Owner: bugs at hypra.fr
User: bugs at hypra.fr
Usertags: hypra
Forwarded: https://bugzilla.mozilla.org/show_bug.cgi?id=1376138

> Steps to reproduce:
> 1. data:text/html,<input type="email"><button>go</button>
> 2. Use accerciser or a similar tool to monitor for state changes
> 3. Type "foo" in the input and press Tab, causing the input to be 
> marked in red
>
> Expected results: A state-changed:invalid-entry event would be emitted 
> so that a screen reader to present the error condition
>
> Actual results: There is no state-changed:invalid-entry emitted.