The <menu> element should act as the list owner of a list element

According to the spec, `<menu>` element should act as the list owner.
https://html.spec.whatwg.org/#the-li-element
> If its parent element is an ol, ul, or menu element, then
> the element is an item of the parent element's list.
> Any element whose computed value of 'display' is 'list-item'
> has a list owner, which is determined as follows:
> If the element has an ol, ul, or menu ancestor, set
> ancestor to the closest such ancestor element.

This patch also modify the `<ol>` element in ref.html to `<menu>`
element. The visual effects of `<ol>` and `<menu>` are inconsistent.

Bug: 40781706
Change-Id: I2776ae7bec16a8b7a9005f19c92444d7be657ecb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5667497
Reviewed-by: Ian Kilpatrick <[email protected]>
Reviewed-by: Joey Arhar <[email protected]>
Commit-Queue: Peng Zhou <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1325899}

html/semantics/grouping-content/the-li-element/grouping-li-reftest-list-owner-menu-ref.html

@@ -2,9 +2,16 @@
 <meta charset="utf-8">
 <title>list owner is calculated to be narest ancestor menu if it exists</title>
 <link rel="author" title="Domenic Denicola" href="mailto:[email protected]">
+<link rel="author" title="Peng Zhou" href="mailto:[email protected]">
 <link rel="help" href="https://html.spec.whatwg.org/multipage/semantics.html#ordinal-value">
 <link rel="help" href="https://html.spec.whatwg.org/multipage/semantics.html#list-owner">
 
+<style>
+  li {
+    list-style-type: decimal;
+  }
+</style>
+
 <p>This test matches if the list displays similar to the following</p>
 
 <pre>1. A
@@ -22,25 +29,25 @@
 
 <hr>
 
-<ol>
+<menu>
   <li value="1">A</li>
   <li value="2">B</li>
   <li value="3">C</li>
   <li value="4">D</li>
   <li value="5">E</li>
-  <ol>
+  <menu>
     <li value="1">F</li>
     <li value="2">G</li>
-  </ol>
+  </menu>
   <li value="6">H</li>
-  <ol>
+  <menu>
     <li value="1">I</li>
     <li value="2">
       J
-      <ol>
+      <menu>
         <li value="1">K</li>
         <li value="2">L</li>
-      </ol>
+      </menu>
     </li>
-  </ol>
-</ol>
+  </menu>
+</menu>