Clarify the unloading document cleanup steps

This fixes the references to "objects whose constructor was invoked from
the Document's Window object" to instead be about the object's relevant
global object. It also fixes some grammatical errors and in general
makes the algorithm easier to read.

Closes #2138.

source

@@ -83392,25 +83392,36 @@ dictionary <dfn>PageTransitionEventInit</dfn> : <span>EventInit</span> {
 
   <ol>
 
+   <li><p>Let <var>window</var> be the <code>Document</code>'s <code>Window</code> object.</p></li>
+
    <li>
 
-    <p><span>Make disappear</span> any <code>WebSocket</code> objects that were created by the <code
-    data-x="dom-WebSocket">WebSocket()</code> constructor from the
-    <code>Document</code>'s <code>Window</code> object.</p>
+    <p>For each <code>WebSocket</code> object <var>webSocket</var> whose <span
+    data-x="concept-relevant-global">relevant global object</span> is equal to <var>window</var>,
+    <span>make disappear</span> <var>webSocket</var>.</p>
 
-    <p>If this affected any <code>WebSocket</code> objects, then set <code>Document</code>'s <i
+    <p>If this affected any <code>WebSocket</code> objects, then set the <code>Document</code>'s <i
     data-x="concept-document-salvageable">salvageable</i> state to false.</p>
 
    </li>
 
-   <li><p>If the <code>Document</code>'s <i data-x="concept-document-salvageable">salvageable</i>
-   state is false, <span data-x="concept-EventSource-forcibly-close">forcibly close</span> any
-   <code>EventSource</code> objects that whose constructor was invoked from the
-   <code>Document</code>'s <code>Window</code> object.</p></li>
+   <li>
+
+    <p>If the <code>Document</code>'s <i data-x="concept-document-salvageable">salvageable</i>
+    state is false, run the following substeps:</p>
+
+    <ol>
+
+     <li><p>For each <code>EventSource</code> object <var>eventSource</var> whose <span
+     data-x="concept-relevant-global">relevant global object</span> is equal to <var>window</var>,
+     <span data-x="concept-EventSource-forcibly-close">forcibly close</span>
+     <var>eventSource</var>.</p></li>
+
+     <li><p>Empty <var>window</var>'s <span>list of active timers</span>.</p></li>
 
-   <li><p>If the <code>Document</code>'s <i data-x="concept-document-salvageable">salvageable</i>
-   state is false, empty the <code>Document</code>'s <code>Window</code>'s <span>list of active
-   timers</span>.</p></li>
+    </ol>
+
+   </li>
 
   </ol>