Editorial: fix window.focus() xref

Author: muzimuzhi

source

@@ -73837,7 +73837,7 @@ END:VCARD</pre>
   <p>User agents are encouraged to ignore calls to this <code data-x="dom-window-blur">blur()</code>
   method entirely.</p>
 
-  <p class="note">Historically, the <code data-x="dom-window-blur">focus()</code> and <code
+  <p class="note">Historically, the <code data-x="dom-window-focus">focus()</code> and <code
   data-x="dom-window-blur">blur()</code> methods actually affected the system-level focus of the
   system widget (e.g., tab or window) that contained the <span>browsing context</span>, but hostile
   sites widely abuse this behavior to the user's detriment.</p>