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

chrome/browser/resources/settings/people_page/setup_fingerprint_dialog.html

 <link rel="import" href="chrome://resources/cr_elements/icons.html">
 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/html/i18n_behavior.html">
 <link rel="import" href="chrome://resources/html/web_ui_listener_behavior.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-button/paper-button.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-icon/iron-icon.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-iconset-svg/iron-iconset-svg.html">
 <link rel="import" href="../icons.html">
 <link rel="import" href="../settings_shared_css.html">
 <link rel="import" href="fingerprint_browser_proxy.html">
@@ skipping 33 matching lines @@
         height: 0;
       }
 
       /* Use this instead of hidden so that the dialog does not resize when the
          problem appears or disappears. */
       #problemDiv[invisible] {
         visibility: hidden;
       }
     </style>
 
-    <dialog is="cr-dialog" id="dialog" on-close="close">
+    <dialog is="cr-dialog" id="dialog" on-close="close"
+        close-text="$i18n{close}">
       <div class="title">$i18n{configureFingerprintTitle}</div>
       <div class="body">
         <div class="settings-box first">
           <span class="middle">[[getInstructionMessage_(step_)]]</span>
         </div>
         <!-- TODO(sammiequon): on-click and on-dblclik are temporary, remove
           once we can interact with the fingerprint hardware -->
         <settings-fingerprint-progress-arc id="arc" on-click="handleClick_"
             on-dblclick="handleDoubleClick_">
         </settings-fingerprint-progress-arc>
@@ skipping 17 matching lines @@
               class$="[[getCloseButtonClass_(step_)]]" on-tap="onClose_">
             [[getCloseButtonText_(step_)]]
           </paper-button>
         </div>
       </div>
     </dialog>
   </template>
 
   <script src="setup_fingerprint_dialog.js"></script>
 </dom-module>