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

chrome/browser/resources/settings/device_page/display.html

 <link rel="import" href="chrome://resources/cr_elements/cr_slider/cr_slider.html">
 <link rel="import" href="chrome://resources/html/i18n_behavior.html">
 <link rel="import" href="chrome://resources/html/md_select_css.html">
 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-flex-layout/classes/iron-flex-layout.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-button/paper-button.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-icon-button/paper-icon-button-light.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-tabs/paper-tabs.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-toggle-button/paper-toggle-button.html">
 <link rel="import" href="display_layout.html">
@@ skipping 116 matching lines @@
             <option value="180">180</option>
             <option value="270">270</option>
           </select>
           <span class="md-select-underline"></span>
         </div>
       </div>
       <div class="settings-box embedded two-line"
           on-tap="onOverscanTap_" hidden$="[[selectedDisplay.isInternal]]"
           actionable>
         <div class="start">
-          <div>$i18n{displayOverscanPageTitle}</div>
-          <div class="secondary">$i18n{displayOverscanPageText}</div>
+          $i18n{displayOverscanPageTitle}
+          <div class="secondary" id="displayOverscanSecondary">
+            $i18n{displayOverscanPageText}
+          </div>
         </div>
-        <button class="subpage-arrow" is="paper-icon-button-light"></button>
+        <button class="subpage-arrow" is="paper-icon-button-light"
+            aria-label="$i18n{displayOverscanPageTitle}"
+            aria-describedby="displayOverscanSecondary"></button>
       </div>
 
       <settings-display-overscan-dialog id="displayOverscan"
           display-id="{{overscanDisplayId}}">
       </settings-display-overscan-dialog>
 
       <div class="settings-box embedded two-line"
           on-tap="onTouchCalibrationTap_"
           hidden$="[[!showTouchCalibrationSetting_(selectedDisplay)]]"
           actionable>
         <div class="start">
-          <div>$i18n{displayTouchCalibrationTitle}</div>
-          <div class="secondary">$i18n{displayTouchCalibrationText}</div>
+          $i18n{displayTouchCalibrationTitle}
+          <div class="secondary" id="touchCalibrationSecondary">
+            $i18n{displayTouchCalibrationText}
+          </div>
         </div>
-        <button class="subpage-arrow" is="paper-icon-button-light"></button>
+        <button class="subpage-arrow" is="paper-icon-button-light"
+            aria-label="$i18n{displayTouchCalibrationTitle}"
+            aria-describedby="touchCalibrationSecondary"></button>
       </div>
     </div>
   </template>
   <script src="display.js"></script>
 </dom-module>