MD Settings: label and describe a bunch of subpage/open-in-new buttons

chrome/browser/resources/settings/a11y_page/a11y_page.html

Index: chrome/browser/resources/settings/a11y_page/a11y_page.html
diff --git a/chrome/browser/resources/settings/a11y_page/a11y_page.html b/chrome/browser/resources/settings/a11y_page/a11y_page.html
index a3eac49f7e7178174392e6d0fac51ebd1ead94ad..432ee614262e9e19b3a05192bf2565854c38bc2f 100644
--- a/chrome/browser/resources/settings/a11y_page/a11y_page.html
+++ b/chrome/browser/resources/settings/a11y_page/a11y_page.html
@@ -29,9 +29,13 @@
               on-tap="onManageAccessibilityFeaturesTap_" actionable>
             <div class="start">
               $i18n{manageAccessibilityFeatures}
-              <div class="secondary">$i18n{moreFeaturesLinkDescription}</div>
+              <div class="secondary" id="themesSecondary">
+                $i18n{moreFeaturesLinkDescription}
+              </div>
             </div>
-            <button class="subpage-arrow" is="paper-icon-button-light"></button>
+            <button class="subpage-arrow" is="paper-icon-button-light"
+                aria-label="$i18n{manageAccessibilityFeatures}"
+                aria-describedby="themesSecondary"></button>
           </div>
         </template>
       </neon-animatable>
@@ -52,9 +56,13 @@
         actionable>
       <div class="start">
         $i18n{moreFeaturesLink}
-        <div class="secondary">$i18n{a11yWebStore}</div>
+        <div class="secondary" id="moreFeaturesSecondary">
+          $i18n{a11yWebStore}
+        </div>
       </div>
-      <button class="icon-external" is="paper-icon-button-light"></button>
+      <button class="icon-external" is="paper-icon-button-light"
+          aria-label="$i18n{moreFeaturesLink}"
+          aria-describedby="moreFeaturesSecondary"></button>
     </div>
 </if>