Improve autofocus and delegatesFocus interaction

Now, when focusing a shadow host with delegates focus set, we try to focus the first focusable area with the autofocus attribute set, instead of just the first focusable area.

Closes #833.

source

@@ -74997,24 +74997,24 @@ END:VCARD</pre>
      <span>currently focused area of a top-level browsing context</span>'s <span>DOM anchor</span>,
      then return null.</li>
 
-     <li>
-      <p>Otherwise:</p>
-
-      <ol>
-       <li>If <var>focus trigger</var> is "<code data-x="">click</code>", then let <var>possible
-       focus delegates</var> be the list of all <span>click focusable</span> <span
-       data-x="focusable area">focusable areas</span> whose <span>DOM anchor</span> is a descendant
-       of <var>focus target</var> in the <span>flat tree</span>.</li>
-
-       <li>Otherwise, let <var>possible focus delegates</var> be the list of all <span
-       data-x="focusable area">focusable areas</span> whose <span>DOM anchor</span> is a descendant
-       of <var>focus target</var> in the <span>flat tree</span>.</li>
-
-       <li>Return the first <span>focusable area</span> in <span>tree order</span> of their <span
-       data-x="DOM anchor">DOM anchors</span> in <var>possible focus delegates</var>, or null if
-       <var>possible focus delegates</var> is empty.</li>
-      </ol>
-     </li>
+     <li><p>If <var>focus trigger</var> is "<code data-x="">click</code>", then let <var>possible
+     focus delegates</var> be the list of all <span>click focusable</span> <span
+     data-x="focusable area">focusable areas</span> whose <span>DOM anchor</span> is a descendant
+     of <var>focus target</var> in the <span>flat tree</span>.</p></li>
+
+     <li><p>Otherwise, let <var>possible focus delegates</var> be the list of all <span
+     data-x="focusable area">focusable areas</span> whose <span>DOM anchor</span> is a descendant
+     of <var>focus target</var> in the <span>flat tree</span>.</p></li>
+
+     <li><p>If any of the <span data-x="focusable area">focusable areas</span> in <var>possible
+     focus delegates</var> have a <span>DOM anchor</span> whose <code
+     data-x="attr-fe-autofocus">autofocus</code> content attribute is specified, then return the
+     first such <span>focusable area</span> in <span>tree order</span> of their <span data-x="DOM
+     anchor">DOM anchors</span>.</p></li>
+
+     <li><p>Return the first <span>focusable area</span> in <span>tree order</span> of their <span
+     data-x="DOM anchor">DOM anchors</span> in <var>possible focus delegates</var>, or null if
+     <var>possible focus delegates</var> is empty.</p></li>
     </ol>
 
     <p class="note">For <span data-x="sequentially focusable">sequential focusability</span>, the