html aam updates for name from heading

This commit supersedes PR #2215

Author: scottaohara

html-aam/index.html

@@ -16816,7 +16816,43 @@ <h4>`iframe` Element Accessible Name Computation</h4>
           </p>
         </section>
         <section>
-          <h4>Section and Grouping Element Accessible Name Computation</h4>
+          <h4>`dialog` Element Accessible Name Computation</h4>
+          <ol>
+            <li>
+              If the `dialog` element has an <a data-cite="wai-aria-1.2/#aria-label">`aria-label`</a> or an <a data-cite="wai-aria-1.2/#aria-labelledby">`aria-labelledby`</a> 
+              attribute the <a data-cite="accname-1.2/#dfn-accessible-name">accessible name</a> is to be calculated using the algorithm defined in
+              <a class="accname">Accessible Name and Description: Computation and API Mappings</a>.
+            </li>
+            <li>
+              If the <a data-cite="accname-1.2/#dfn-accessible-name">accessible name</a> is still empty, then: if the `dialog` element has a
+              <a href="https://dom.spec.whatwg.org/#concept-tree-descendant">descendant</a> element with a role of `heading`, then use the 
+              <a data-cite="accname-1.2/#mapping_additional_nd_te">text equivalent computation</a> of the element as defined in
+              <a data-cite="accname-1.2/#comp_name_from_heading">accname: Name from Heading</a>.
+            </li>
+            <li>Otherwise, use the `title` attribute.</li>
+            <li>If none of the above yield a usable text string there is no <a data-cite="accname-1.2/#dfn-accessible-name">accessible name</a>.</li>
+          </ol>
+        </section>
+        <section>
+          <h4>`article` Element Accessible Name Computation</h4>
+          <ol>
+            <li>
+              If the `article` element has an <a data-cite="wai-aria-1.2/#aria-label">`aria-label`</a> or an <a data-cite="wai-aria-1.2/#aria-labelledby">`aria-labelledby`</a> 
+              attribute the <a data-cite="accname-1.2/#dfn-accessible-name">accessible name</a> is to be calculated using the algorithm defined in
+              <a class="accname">Accessible Name and Description: Computation and API Mappings</a>.
+            </li>
+            <li>
+              If the <a data-cite="accname-1.2/#dfn-accessible-name">accessible name</a> is still empty, then: if the `dialog` element has a
+              <a href="https://dom.spec.whatwg.org/#concept-tree-descendant">descendant</a> element with a role of `heading`, then use the 
+              <a data-cite="accname-1.2/#mapping_additional_nd_te">text equivalent computation</a> of the element as defined in
+              <a data-cite="accname-1.2/#comp_name_from_heading">accname: Name from Heading</a>.
+            </li>
+            <li>Otherwise, use the `title` attribute.</li>
+            <li>If none of the above yield a usable text string there is no <a data-cite="accname-1.2/#dfn-accessible-name">accessible name</a>.</li>
+          </ol>
+        </section>
+        <section>
+          <h4>Other Section and Grouping Element Accessible Name Computation</h4>
           <ol>
             <li>
               If the element has an <a data-cite="wai-aria-1.2/#aria-label">`aria-label`</a> or an <a data-cite="wai-aria-1.2/#aria-labelledby">`aria-labelledby`</a> attribute the