MD Settings: add a bunch of dialog (X) aria-labels

chrome/browser/resources/settings/site_settings/site_data.html

 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/cr_elements/cr_dialog/cr_dialog.html">
 <link rel="import" href="chrome://resources/cr_elements/icons.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-flex-layout/iron-flex-layout-classes.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-icon/iron-icon.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-icon-button/paper-icon-button-light.html">
 <link rel="import" href="../settings_page/settings_subpage_search.html">
 <link rel="import" href="../settings_shared_css.html">
 <link rel="import" href="cookie_tree_behavior.html">
 <link rel="import" href="site_settings_behavior.html">
@@ skipping 50 matching lines @@
             </button>
           </div>
           <button class="subpage-arrow" is="paper-icon-button-light"
               aria-label="[[item.site]]"
               aria-describedby="siteSecondary"></button>
         </div>
       </template>
     </div>
 
     <!-- Confirm Delete dialog -->
-    <dialog is="cr-dialog" id="confirmDeleteDialog">
+    <dialog is="cr-dialog" id="confirmDeleteDialog" close-text="$i18n{close}">
       <div class="title">$i18n{siteSettingsCookieRemoveDialogTitle}</div>
       <div class="body">[[confirmationDeleteMsg_]]</div>
       <div class="button-container">
         <paper-button class="cancel-button" on-tap="onCloseDialog_">
           $i18n{cancel}
         </paper-button>
         <paper-button class="action-button" on-tap="onConfirmDelete_">
           $i18n{siteSettingsCookiesClearAll}
         </paper-button>
       </div>
     </dialog>
   </template>
   <script src="cookie_info.js"></script>
   <script src="cookie_tree_node.js"></script>
   <script src="site_data.js"></script>
 </dom-module>