Consider media element playback ended after the loop attribute is set

Before this change, allowing playback to end, then subsequently setting the loop attribute to true, would result in the ended attribute being false, and playback not restarting when the play steps are run.

Fixes #11775

Author: Zaggy1024

source

@@ -39612,8 +39612,9 @@ interface <dfn interface>MediaError</dfn> {
 
      <li><p>The <span>direction of playback</span> is forwards, and</p></li>
 
-     <li><p>The <span>media element</span> does not have a <code
-     data-x="attr-media-loop">loop</code> attribute specified.</p></li>
+     <li><p>The <span>media element</span> did not have a <code
+     data-x="attr-media-loop">loop</code> attribute specified the last time that playback
+     <a href="#reaches-the-end">reached the end of the media resource</a>.</p></li>
     </ul>
 
     <p>Or:</p>