Row Role: allow aria-posinset and aria-setsize for issue 558 (#789)

- Removed paragraph about aria-expanded in treegrids.
- Add paragraph with two normative statements:
  * Authors must only use setsize, posinset, level, and expanded
    attributes in treegrids
  * User agents should only expose them in treegrids
- Modified allowed states and properties to allow aria-posinset and
  aria-setsize.

index.html

@@ -5629,8 +5629,8 @@ <h5>Presentational Roles Conflict Resolution</h5>
 			<rdef>row</rdef>
 			<div class="role-description">
 				<p>A row of cells in a tabular container.</p>
-				<p>Rows contain <rref>cell</rref> or <rref>gridcell</rref> <a>elements</a>, and thus serve to organize the <rref>table</rref> or <rref>grid</rref>.</p>
-				<p>In a <rref>treegrid</rref>, authors MAY mark rows as expandable, using the <sref>aria-expanded</sref> <a>attribute</a> to indicate the present status. This is not the case for an ordinary <rref>table</rref> or <rref>grid</rref>, in which the <sref>aria-expanded</sref> attribute is not present.</p>
+				<p>Rows contain <rref>cell</rref> or <rref>gridcell</rref> <a>elements</a>, and thus serve to organize a <rref>table</rref>, <rref>grid</rref>, or <rref>treegrid</rref>.</p>
+				<p> While the row role can be used in <rref>tables</rref>, <rref>grids</rref>, and <rref>treegrids</rref>, the semantics of <sref>aria-expanded</sref>, <pref>aria-posinset</pref>, <pref>aria-setsize</pref>, and <pref>aria-level</pref> are only applicable to the hierarchical structure of an interactive tree grid. Therefore, authors MUST NOT apply <sref>aria-expanded</sref>, <pref>aria-posinset</pref>, <pref>aria-setsize</pref>, and <pref>aria-level</pref> to a <rref>row</rref> that descends from a <rref>table</rref> or <rref>grid</rref>, and user agents SHOULD NOT expose any of these four properties to assistive technologies unless the <rref>row</rref> descends from a <rref>treegrid</rref>.</p>
 				<p>Authors MUST ensure <a>elements</a> with <a>role</a> <code>row</code> are contained in, or <a>owned</a> by, an element with the role <rref>table</rref>, <rref>grid</rref>, <rref>rowgroup</rref>, or <rref>treegrid</rref>.</p>
 			</div>
 			<table class="role-features">
@@ -5700,7 +5700,9 @@ <h5>Presentational Roles Conflict Resolution</h5>
 								<li><pref>aria-colindex</pref></li>
 								<li><sref>aria-expanded</sref></li>
 								<li><pref>aria-level</pref></li>
+								<li><pref>aria-posinset</pref></li>
 								<li><pref>aria-rowindex</pref></li>
+								<li><pref>aria-setsize</pref></li>
 								<li><sref>aria-selected</sref></li>
 							</ul>
 						</td>
@@ -11689,6 +11691,7 @@ <h2>Change Log</h2>
 		<h2>Substantive changes since the last public working draft</h2>
 		<ul>
 			<!-- EdNote: After each WD publish, move contents of this list into the next one below. -->
+			<li>04-Sep-2019: Allow aria-posinset and aria-setsize on row when used in a treegrid.</li>
 			<li>04-Sep-2019: Add aria-expanded support to application and checkbox roles.</li>
 			<li>04-Sep-2019: Remove aria-expanded support from the following roles: alert, alertdialog, article, banner, blockquote, caption, cell, complementary, contentinfo, definition, deletion, dialog, directory, feed, figure, form, grid, group, heading, img, insertion, label, landmark, legend, list, listitem, log, main, marquee, math, menu, menubar, navigation, note, paragraph, radiogroup, region, search, select, status, subscript, superscript, table, tabpanel, term, time, timer, toolbar, tooltip, tree, treegrid.</li>
 			<li>04-Sep-2019: Remove children-presentational=true from math role</li>
@@ -11707,7 +11710,6 @@ <h2>Substantive changes since the <a href="https://www.w3.org/TR/wai-aria-1.1/">
 			<li>05-Oct-2018: Role <rref>spinbutton</rref>: Change the default value of <pref>aria-valuenow</pref> from <code>0</code> to "there is no current value." Also add <pref>aria-valuetext</pref> as a supported property.</li>
 			<li>05-Oct-2018: Role <rref>spinbutton</rref>: allow empty values, no min, no max, and structure with sibling steppers</li>
 			<li>21-Aug-2018: Correct normative language in <rref>rowheader</rref> to be consistent with required states and properties.</li>
-			<li>21-Aug-2018: Allow <sref>aria-posinset</sref> and <sref>aria-setsize</sref> on <rref>row</rref> when used in a <rref>treegrid</rref>.</li>
 			<li>21-Jun-2018: Allow <rref>group</rref> as child of <rref>listbox</rref>.</li>
 			<li>21-Jun-2018: Resolve inconsistencies around group ownership of <rref>menuitem</rref>, <rref>menuitemcheckbox</rref> and <rref>menuitemradio</rref>.</li>
 			<li>31-May-2018: Add <rref>blockquote</rref>, <rref>caption</rref>, and <rref>paragraph</rref> roles.</li>