Record timing info for event handling

This feeds into "Long Animation Frame" timing.

dom.bs

@@ -1630,6 +1630,9 @@ and an optional <var>legacyOutputDidListenersThrowFlag</var>, run these steps:
    <li><p>If <var>listener</var>'s <a for="event listener">passive</a> is true, then set
    <var>event</var>'s <a>in passive listener flag</a>.
 
+   <li><p>If <var>global</var> is a {{Window}} object, then
+   <a>record timing info for event listener</a> given <var>event</var> and <var>listener</var>.
+
    <li>
     <p><a>Call a user object's operation</a> with <var>listener</var>'s
     <a for="event listener">callback</a>, "<code>handleEvent</code>", « <var>event</var> », and