[] (0) Add support for ARIA aria-level for headings; try confusing pe…

…ople less with <hgroup>.

git-svn-id: http://svn.whatwg.org/webapps@3726 340c8d12-0b0e-0410-8428-c7bf67bfef74

index

     <td><code title=attr-aria-role-contentinfo>contentinfo</code> role

    <tr><td><code><a href=#the-h1,-h2,-h3,-h4,-h5,-and-h6-elements>h1</a></code> element that does not have an <code><a href=#the-hgroup-element>hgroup</a></code> ancestor
     <td><code title=attr-aria-role-heading>heading</code> role
     <td><code title=attr-aria-role-heading>heading</code> role, with the <code title=attr-aria-level>aria-level</code> property set to the element's <a href=#outline-depth>outline depth</a>

    <tr><td><code><a href=#the-h1,-h2,-h3,-h4,-h5,-and-h6-elements>h2</a></code> element that does not have an <code><a href=#the-hgroup-element>hgroup</a></code> ancestor
     <td><code title=attr-aria-role-heading>heading</code> role
     <td><code title=attr-aria-role-heading>heading</code> role, with the <code title=attr-aria-level>aria-level</code> property set to the element's <a href=#outline-depth>outline depth</a>

    <tr><td><code><a href=#the-h1,-h2,-h3,-h4,-h5,-and-h6-elements>h3</a></code> element that does not have an <code><a href=#the-hgroup-element>hgroup</a></code> ancestor
     <td><code title=attr-aria-role-heading>heading</code> role
     <td><code title=attr-aria-role-heading>heading</code> role, with the <code title=attr-aria-level>aria-level</code> property set to the element's <a href=#outline-depth>outline depth</a>

    <tr><td><code><a href=#the-h1,-h2,-h3,-h4,-h5,-and-h6-elements>h4</a></code> element that does not have an <code><a href=#the-hgroup-element>hgroup</a></code> ancestor
     <td><code title=attr-aria-role-heading>heading</code> role
     <td><code title=attr-aria-role-heading>heading</code> role, with the <code title=attr-aria-level>aria-level</code> property set to the element's <a href=#outline-depth>outline depth</a>

    <tr><td><code><a href=#the-h1,-h2,-h3,-h4,-h5,-and-h6-elements>h5</a></code> element that does not have an <code><a href=#the-hgroup-element>hgroup</a></code> ancestor
     <td><code title=attr-aria-role-heading>heading</code> role
     <td><code title=attr-aria-role-heading>heading</code> role, with the <code title=attr-aria-level>aria-level</code> property set to the element's <a href=#outline-depth>outline depth</a>

    <tr><td><code><a href=#the-h1,-h2,-h3,-h4,-h5,-and-h6-elements>h6</a></code> element that does not have an <code><a href=#the-hgroup-element>hgroup</a></code> ancestor
     <td><code title=attr-aria-role-heading>heading</code> role
     <td><code title=attr-aria-role-heading>heading</code> role, with the <code title=attr-aria-level>aria-level</code> property set to the element's <a href=#outline-depth>outline depth</a>

    <tr><td><code><a href=#the-header-element>header</a></code> element
     <td><code title=attr-aria-role-banner>banner</code> role

    <tr><td><code><a href=#the-hgroup-element>hgroup</a></code> element
     <td><code title=attr-aria-role-heading>heading</code> role
     <td><code title=attr-aria-role-heading>heading</code> role, with the <code title=attr-aria-level>aria-level</code> property set to the element's <a href=#outline-depth>outline depth</a>

    <tr><td><code><a href=#the-hr-element>hr</a></code> element
     <td><code title=attr-aria-role-separator>separator</code> role
  multiple levels, such as subheadings, alternative titles, or
  taglines.</p>

  <p class=note>The point of <code><a href=#the-hgroup-element>hgroup</a></code> is to mask an
  <code><a href=#the-h1,-h2,-h3,-h4,-h5,-and-h6-elements>h2</a></code> element (that acts as a secondary title) from the
  <a href=#outline>outline</a> algorithm.</p><!--
  http://www.brucelawson.co.uk/2009/html-5-is-a-mess/#comment-618895
  -->

  <p>For the purposes of document summaries, outlines, and the like,
  the text of <code><a href=#the-hgroup-element>hgroup</a></code> elements is defined to be the text
  of the highest <a href=#rank title=rank>ranked</a>
 &lt;h2&gt;Or: How I Learned to Stop Worrying and Love the Bomb&lt;/h2&gt;
&lt;/hgroup&gt;</pre>

  <p>The point of using <code><a href=#the-hgroup-element>hgroup</a></code> in these examples is to
  mask the <code><a href=#the-h1,-h2,-h3,-h4,-h5,-and-h6-elements>h2</a></code> element (which acts as a secondary title)
  from the <a href=#outline>outline</a> algorithm.</p><!--
  http://www.brucelawson.co.uk/2009/html-5-is-a-mess/#comment-618895
  -->

  </div>


  always takes the user to the top of the document, regardless of
  where the first heading in the <code><a href=#the-body-element-0>body</a></code> is to be found.</p>

  <p>The <dfn id=outline-depth>outline depth</dfn> of a <a href=#heading-content>heading content</a>
  element associated with a <a href=#concept-section title=concept-section>section</a> <var title="">section</var>
  is the number of <a href=#concept-section title=concept-section>sections</a> that
  are ancestors of <var title="">section</var> in the
  <a href=#outline>outline</a> that <var title="">section</var> finds itself
  in when the <a href=#outline title=outline>outlines</a> of its
  <code>Document</code>'s elements are created, plus 1. The
  <a href=#outline-depth>outline depth</a> of a <a href=#heading-content>heading content</a> element
  not associated with a <a href=#concept-section title=concept-section>section</a>
  is 1.</p>

  <div class=note>

   <p>The following JavaScript function shows how the tree walk could

source

@@ -9349,35 +9349,35 @@ http://software.hixie.ch/utilities/js/live-dom-viewer/?%3C%21DOCTYPE%20HTML%3E%0

    <tr>
     <td><code>h1</code> element that does not have an <code>hgroup</code> ancestor
     <td><code title="attr-aria-role-heading">heading</code> role
     <td><code title="attr-aria-role-heading">heading</code> role, with the <code title="attr-aria-level">aria-level</code> property set to the element's <span>outline depth</span>

    <tr>
     <td><code>h2</code> element that does not have an <code>hgroup</code> ancestor
     <td><code title="attr-aria-role-heading">heading</code> role
     <td><code title="attr-aria-role-heading">heading</code> role, with the <code title="attr-aria-level">aria-level</code> property set to the element's <span>outline depth</span>

    <tr>
     <td><code>h3</code> element that does not have an <code>hgroup</code> ancestor
     <td><code title="attr-aria-role-heading">heading</code> role
     <td><code title="attr-aria-role-heading">heading</code> role, with the <code title="attr-aria-level">aria-level</code> property set to the element's <span>outline depth</span>

    <tr>
     <td><code>h4</code> element that does not have an <code>hgroup</code> ancestor
     <td><code title="attr-aria-role-heading">heading</code> role
     <td><code title="attr-aria-role-heading">heading</code> role, with the <code title="attr-aria-level">aria-level</code> property set to the element's <span>outline depth</span>

    <tr>
     <td><code>h5</code> element that does not have an <code>hgroup</code> ancestor
     <td><code title="attr-aria-role-heading">heading</code> role
     <td><code title="attr-aria-role-heading">heading</code> role, with the <code title="attr-aria-level">aria-level</code> property set to the element's <span>outline depth</span>

    <tr>
     <td><code>h6</code> element that does not have an <code>hgroup</code> ancestor
     <td><code title="attr-aria-role-heading">heading</code> role
     <td><code title="attr-aria-role-heading">heading</code> role, with the <code title="attr-aria-level">aria-level</code> property set to the element's <span>outline depth</span>

    <tr>
     <td><code>header</code> element
     <td><code title="attr-aria-role-banner">banner</code> role

    <tr>
     <td><code>hgroup</code> element
     <td><code title="attr-aria-role-heading">heading</code> role
     <td><code title="attr-aria-role-heading">heading</code> role, with the <code title="attr-aria-level">aria-level</code> property set to the element's <span>outline depth</span>

    <tr>
     <td><code>hr</code> element
  multiple levels, such as subheadings, alternative titles, or
  taglines.</p>

  <p class="note">The point of <code>hgroup</code> is to mask an
  <code>h2</code> element (that acts as a secondary title) from the
  <span>outline</span> algorithm.</p><!--
  http://www.brucelawson.co.uk/2009/html-5-is-a-mess/#comment-618895
  -->

  <p>For the purposes of document summaries, outlines, and the like,
  the text of <code>hgroup</code> elements is defined to be the text
  of the highest <span title="rank">ranked</span>
 &lt;h2&gt;Or: How I Learned to Stop Worrying and Love the Bomb&lt;/h2&gt;
&lt;/hgroup&gt;</pre>

  <p>The point of using <code>hgroup</code> in these examples is to
  mask the <code>h2</code> element (which acts as a secondary title)
  from the <span>outline</span> algorithm.</p><!--
  http://www.brucelawson.co.uk/2009/html-5-is-a-mess/#comment-618895
  -->

  </div>


  always takes the user to the top of the document, regardless of
  where the first heading in the <code>body</code> is to be found.</p>

  <p>The <dfn>outline depth</dfn> of a <span>heading content</span>
  element associated with a <span
  title="concept-section">section</span> <var title="">section</var>
  is the number of <span title="concept-section">sections</span> that
  are ancestors of <var title="">section</var> in the
  <span>outline</span> that <var title="">section</var> finds itself
  in when the <span title="outline">outlines</span> of its
  <code>Document</code>'s elements are created, plus 1. The
  <span>outline depth</span> of a <span>heading content</span> element
  not associated with a <span title="concept-section">section</span>
  is 1.</p>

  <div class="note">

   <p>The following JavaScript function shows how the tree walk could