Collapse disowned into opener browsing context

Tests: TODO.

Fixes #5569.

source

@@ -86154,8 +86154,6 @@ dictionary <dfn dictionary>WindowPostMessageOptions</dfn> : <span>StructuredSeri
 
    <li><p>If <var>current</var> is null, then return null.</p></li>
 
-   <li><p>If <var>current</var>'s <span>disowned</span> is true, then return null.</p></li>
-
    <li><p>If <var>current</var>'s <span>opener browsing context</span> is null, then return
    null.</p></li>
 
@@ -86168,29 +86166,14 @@ dictionary <dfn dictionary>WindowPostMessageOptions</dfn> : <span>StructuredSeri
   <ol>
    <li><p>If the given value is null and <span>this</span>'s <span data-x="window bc">browsing
    context</span> is non-null, then set <span>this</span>'s <span data-x="window bc">browsing
-   context</span>'s <span>disowned</span> to true.</p></li>
+   context</span>'s <span>opener browsing context</span> to null.</p></li>
 
    <li><p>If the given value is non-null, then return ?
    <span>OrdinaryDefineOwnProperty</span>(<span>this</span>, "<code data-x="">opener</code>", {
    [[Value]]: the given value, [[Writable]]: true, [[Enumerable]]: true, [[Configurable]]: true
    }).</p></li>
   </ol>
 
-  <div class="note">
-   <p>If a <span>browsing context</span>'s <span>disowned</span> is true, its <code
-   data-x="dom-opener">window.opener</code> attribute is null. That prevents scripts in the
-   <span>browsing context</span> from changing any properties of its <span>opener browsing
-   context</span>'s <code>Window</code> object (i.e., the <code>Window</code> object from which the
-   <span>browsing context</span> was created).</p>
-
-   <p>Otherwise, if a <span>browsing context</span>'s <span>disowned</span> is false, then scripts
-   in that <span>browsing context</span> can use <code data-x="dom-opener">window.opener</code> to
-   change properties of its <span>opener browsing context</span>'s <code>Window</code> object. For
-   example, a script running in the <span>browsing context</span> can change the value of <code
-   data-x="">window.opener.location</code>, causing the <span>opener browsing context</span> to
-   navigate to a completely different document.</p>
-  </div>
-
   <p>The <dfn attribute for="Window"><code data-x="dom-parent">parent</code></dfn> getter steps
   are:</p>
 
@@ -89358,8 +89341,6 @@ interface <dfn interface>BeforeUnloadEvent</dfn> : <span>Event</span> {
    <li><p>An <dfn data-x="opener-origin-at-creation">opener origin at creation</dfn>, an
    <span>origin</span> or null, initially null.</p>
 
-   <li><p>A <dfn id="disowned-its-opener">disowned</dfn> boolean, initially false.</p></li>
-
    <li>
     <p>An <dfn>is popup</dfn> boolean, initially false.</p>
 
@@ -91318,7 +91299,7 @@ location.href = '#foo';</code></pre>
 
      <li><p><var>historyEntry</var>'s <span data-x="she-document">document</span>'s <span
      data-x="concept-document-bc">browsing context</span> is not an <span>auxiliary browsing
-     context</span> whose <span>disowned</span> is false; and</p></li>
+     context</span> whose <span>opener browsing context</span> is non-null; and</p></li>
 
      <li><p><var>historyEntry</var>'s <span data-x="she-document">document</span>'s <span
      data-x="concept-document-origin">origin</span> is not <var>navigable</var>'s <span
@@ -93605,7 +93586,7 @@ location.href = '#foo';</code></pre>
 
          <li><p><var>targetEntry</var>'s <span data-x="she-document">document</span>'s <span
          data-x="concept-document-bc">browsing context</span> is not an <span>auxiliary browsing
-         context</span> whose <span>disowned</span> is false; and</p></li>
+         context</span> whose <span>opener browsing context</span> is non-null; and</p></li>
 
          <li><p><var>targetEntry</var>'s <span data-x="she-document">document</span>'s <span
          data-x="concept-document-origin">origin</span> is not <var>oldOrigin</var></p></li>