Add 'meter' role

Addresses github issue #451.

Author: joanmarie

index.html

@@ -618,6 +618,7 @@ <h3>Widget Roles</h3>
 				<li><rref>menuitem</rref></li>
 				<li><rref>menuitemcheckbox</rref></li>
 				<li><rref>menuitemradio</rref></li>
+				<li><rref>meter</rref></li>
 				<li><rref>option</rref></li>
 <!-- FIXME: This is commented out because the ARIA Working Group agreed to move the password role to ARIA 2.0,
      but we've not branched for 1.1 yet. Once we have branched, this section should be deleted from the 1.1
@@ -4051,6 +4052,93 @@ <h4>Plain HTML or Polyfill DOM Result of the MathML Quadratic Formula</h4>
 				</tbody>
 			</table>
 		</div>
+		<div class="role" id="meter">
+			<rdef>meter</rdef>
+			<div class="role-description">
+				<p>An <a>element</a> that represents a scalar measurement within a known range, or a fractional value. See related <rref>progress</rref>.</p>
+				<p>Authors MUST NOT use the <code>meter</code> role to represent a value whose minimum and maximum values are unknown and MUST use <pref>aria-valuemin</pref> and <pref>aria-valuemax</pref> to make these values available to assistive technologies.</p>
+				<p>Authors SHOULD NOT use the <code>meter</code> role to indicate progress; the <rref>progressbar</rref> role exists to address that need.</p>
+				<p class="note">At the present time, there are no <abbr title="Accessible Rich Internet Applications">WAI-ARIA</abbr> properties corresponding to the <code>low</code>, <code>optimum</code>, and <code>high</code> attributes supported on <a href="https://www.w3.org/TR/html50/forms.html#the-meter-element"><abbr title="Hypertext Markup Language">HTML</abbr> <code>meter</code></a>. The addition of these properties will be considered for ARIA version 1.3.</p>
+				<p>Authors wishing to communicate that the displayed value is low, optimum, or high SHOULD do so by including this information in <pref>aria-valuetext</pref>.</p>
+			</div>
+			<table class="role-features">
+				<caption>Characteristics:</caption>
+				<thead>
+					<tr>
+						<th scope="col">Characteristic</th>
+						<th scope="col">Value</th>
+					</tr>
+				</thead>
+				<tbody>
+					<tr>
+						<th class="role-abstract-head" scope="row">Is Abstract:</th>
+						<td class="role-abstract"> </td>
+					</tr>
+					<tr>
+						<th class="role-parent-head" scope="row">Superclass Role:</th>
+						<td class="role-parent"><rref>range</rref></td>
+					</tr>
+					<tr>
+						<th class="role-children-head" scope="row">Subclass Roles:</th>
+						<td class="role-children">Placeholder</td>
+					</tr>
+					<tr>
+						<th class="role-base-head" scope="row">Base Concept:</th>
+						<td class="role-base"> </td>
+					</tr>
+					<tr>
+						<th class="role-related-head" scope="row">Related Concepts:</th>
+						<td class="role-related"><a href="https://www.w3.org/TR/html50/forms.html#the-meter-element"><abbr title="Hypertext Markup Language">HTML</abbr> <code>meter</code></a></td>
+					</tr>
+					<tr>
+						<th class="role-scope-head" scope="row">Required Context Role:</th>
+						<td class="role-scope"> </td>
+					</tr>
+					<tr>
+						<th class="role-mustcontain-head" scope="row">Required Owned Elements:</th>
+						<td class="role-mustcontain"> </td>
+					</tr>
+					<tr>
+						<th class="role-required-properties-head">Required States and Properties:</th>
+						<td class="role-required-properties">
+							<ul>
+								<li><pref>aria-valuemax</pref></li>
+								<li><pref>aria-valuemin</pref></li>
+								<li><pref>aria-valuenow</pref></li>
+							</ul>
+						</td>
+					</tr>
+					<tr>
+						<th class="role-properties-head" scope="row">Supported States and Properties:</th>
+						<td class="role-properties"> </td>
+					</tr>
+					<tr>
+						<th class="role-inherited-head" scope="row">Inherited States and Properties:</th>
+						<td class="role-inherited">Placeholder</td>
+					</tr>
+					<tr>
+						<th class="role-namefrom-head" scope="row">Name From:</th>
+						<td class="role-namefrom">author</td>
+					</tr>
+					<tr>
+						<th class="role-namerequired-head" scope="row">Accessible Name Required:</th>
+						<td class="role-namerequired">True</td>
+					</tr>
+					<tr>
+						<th class="role-namerequired-inherited-head" scope="row">Inherits Name Required:</th>
+						<td class="role-namerequired-inherited"> </td>
+					</tr>
+					<tr>
+						<th class="role-childpresentational-head" scope="row">Children Presentational:</th>
+						<td class="role-childpresentational">True</td>
+					</tr>
+					<tr>
+						<th class="role-presentational-inherited-head" scope="row">Inherits Presentational:</th>
+						<td class="role-presentational-inherited"> </td>
+					</tr>
+				</tbody>
+			</table>
+		</div>
 		<div class="role" id="menu">
 			<rdef>menu</rdef>
 			<div class="role-description">