Align with DOM DocumentFragment adoption changes

Complements whatwg/dom#819.

Tests: web-platform-tests/wpt#22504.

Author: annevk

source

@@ -58444,7 +58444,8 @@ interface <dfn>HTMLTemplateElement</dfn> : <span>HTMLElement</span> {
    </li>
 
    <li><p><span data-x="concept-node-adopt">Adopt</span> <var>node</var>'s
-   <span>template contents</span> (a <code>DocumentFragment</code> object) into <var>doc</var>.</p></li>
+   <span>template contents</span> (a <code>DocumentFragment</code> object) into <var>doc</var>, with
+   <var>forceDocumentFragmentAdoption</var> set to true.</p></li>
   </ol>
 
   <p>The <dfn><code data-x="dom-template-content">content</code></dfn> IDL attribute must return the