Remove noopener from tokenizedFeatures

Apparently CSSOM needs to react differently if it's there.

Helps with #1902.

source

@@ -2503,8 +2503,9 @@ a.setAttribute('href', 'https://example.com/'); // change the content attribute
      <li><dfn data-x-href="https://infra.spec.whatwg.org/#skip-ascii-whitespace">skip ASCII whitespace</dfn></li>
      <li>The <dfn data-x-href="https://infra.spec.whatwg.org/#ordered-map">ordered map</dfn> data structure and the associated definitions for
              <dfn data-x="map exists" data-x-href="https://infra.spec.whatwg.org/#map-exists">exists</dfn>,
-             <dfn data-x="map get" data-x-href="https://infra.spec.whatwg.org/#map-get">getting the value of an entry</dfn>, and
-             <dfn data-x="map set" data-x-href="https://infra.spec.whatwg.org/#map-set">setting the value of an entry</dfn></li>
+             <dfn data-x="map get" data-x-href="https://infra.spec.whatwg.org/#map-get">getting the value of an entry</dfn>,
+             <dfn data-x="map set" data-x-href="https://infra.spec.whatwg.org/#map-set">setting the value of an entry</dfn>, and
+             <dfn data-x="map remove" data-x-href="https://infra.spec.whatwg.org/#map-remove">removing an entry</dfn></li>
      <li>The <dfn data-x-href="https://infra.spec.whatwg.org/#list">list</dfn> data structure and the associated definitions for
              <dfn data-x="list append" data-x-href="https://infra.spec.whatwg.org/#list-append">append</dfn>,
              <dfn data-x="list replace" data-x-href="https://infra.spec.whatwg.org/#list-remove">replace</dfn>,
@@ -78391,8 +78392,19 @@ callback <dfn>FrameRequestCallback</dfn> = void (<span>DOMHighResTimeStamp</span
    <li><p>Let <var>tokenizedFeatures</var> be the result of <span
    data-x="concept-window-open-features-tokenize">tokenizing</span> <var>features</var>.</p></li>
 
-   <li><p>Let <var>noopener</var> be true if <var>tokenizedFeatures</var> <span data-x="map
-   exists">contains</span> an entry with the key "<code data-x="">noopener</code>"</p></li>
+   <li><p>Let <var>noopener</var> be false.</p></li>
+
+   <li>
+    <p>If <var>tokenizedFeatures</var>["<code data-x="">noopener</code>"] <span data-x="map
+    exists">exists</span>, then:</p>
+
+    <ol>
+     <li><p>Set <var>noopener</var> to true.</p></li>
+
+     <li><p><span data-x="map remove">Remove</span> <var>tokenizedFeatures</var>["<code
+     data-x="">noopener</code>"].</p></li>
+    </ol>
+   </li>
 
    <li>
     <p>Let <var>target browsing context</var> and <var>new</var> be the result of applying <span>the