Remove noopener/noreferrer from tokenizedFeatures

Otherwise CSSOM will assume it's more than a new window and treat it like a popup or some such.

Helps with #1902.

Tests: web-platform-tests/wpt#16330 & web-platform-tests/wpt#16658.

source

@@ -78670,15 +78670,33 @@ dictionary <dfn>WindowPostMessageOptions</dfn> : <span>PostMessageOptions</span>
 
    <li><p>Let <var>noopener</var> and <var>noreferrer</var> be false.</p></li>
 
-   <li><p>If <var>tokenizedFeatures</var> <span data-x="map exists">contains</span> an entry with
-   the key "<code data-x="">noopener</code>", then set <var>noopener</var> to the result of <span
-   data-x="concept-window-open-features-parse-boolean">parsing
-   <var>tokenizedFeatures["noopener"]</var> as a boolean feature</span>.</p></li>
-
-   <li><p>If <var>tokenizedFeatures</var> <span data-x="map exists">contains</span> an entry with
-   the key "<code data-x="">noreferrer</code>", then set <var>noreferrer</var> to the result of
-   <span data-x="concept-window-open-features-parse-boolean">parsing
-   <var>tokenizedFeatures["noreferrer"]</var> as a boolean feature</span>.</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 the result of <span
+     data-x="concept-window-open-features-parse-boolean">parsing <var>tokenizedFeatures</var>["<code
+     data-x="">noopener</code>"] as a boolean feature</span>.</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>If <var>tokenizedFeatures</var>["<code data-x="">noreferrer</code>"] <span data-x="map
+    exists">exists</span>, then:</p>
+
+    <ol>
+     <li><p>Set <var>noreferrer</var> to the result of <span
+     data-x="concept-window-open-features-parse-boolean">parsing <var>tokenizedFeatures</var>["<code
+     data-x="">noreferrer</code>"] as a boolean feature</span>.</p></li>
+
+     <li><p><span data-x="map remove">Remove</span> <var>tokenizedFeatures</var>["<code
+     data-x="">noreferrer</code>"].</p></li>
+    </ol>
+   </li>
 
    <li><p>If <var>noreferrer</var> is true, then set <var>noopener</var> to true.</p></li>