[cssom-view] for w3c#8103

Author: Adam Argyle

cssom-view-1/Overview.bs

@@ -1695,6 +1695,7 @@ interface VisualViewport : EventTarget {
 
   attribute EventHandler onresize;
   attribute EventHandler onscroll;
+  attribute EventHandler onscrollend;
 };
 </pre>
 
@@ -1746,6 +1747,8 @@ The <dfn attribute for=VisualViewport>scale</dfn> attribute must run these steps
 
 <dfn attribute for=VisualViewport>onscroll</dfn> is the <a>event handler IDL attribute</a> for the <a event>scroll</a> event.
 
+<dfn attribute for=VisualViewport>onscrollend</dfn> is the <a>event handler IDL attribute</a> for the <a event>scrollend</a> event.
+
 <h2 id=events>Events</h2>
 
 <h3 id=resizing-viewports>Resizing viewports</h3>