Add changelog entry

index.html

@@ -12680,7 +12680,7 @@ <h2>Change Log</h2>
 		<h2>Substantive changes since the last public working draft</h2>
 		<ul>
 			<!-- EdNote: After each WD publish, move contents of this list into the next one below. -->
-			<li>04-June-2019: Make aria-valuemin and aria-valuemax supported, rather than required, properties of focusable separator and slider</li>
+			<li>04-June-2019: Make aria-valuemin and aria-valuemax supported, rather than required, properties of focusable separator, slider, and scrollbar. Make aria-orientation a supported, rather than required, property of scrollbar.</li>
 			<li>02-May-2019: Add strong and emphasis roles</li>
 			<li>02-May-2019: Add aria-required as a supported property of checkbox</li>
 			<li>02-May-2019: Add code role</li>