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

chrome/browser/resources/settings/internet_page/internet_page.html

 <link rel="import" href="chrome://resources/cr_elements/cr_expand_button/cr_expand_button.html">
 <link rel="import" href="chrome://resources/cr_elements/icons.html">
 <link rel="import" href="chrome://resources/cr_elements/network/cr_onc_types.html">
 <link rel="import" href="chrome://resources/html/i18n_behavior.html">
 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-icon/iron-icon.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/neon-animation/neon-animatable.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-icon-button/paper-icon-button-light.html">
 <link rel="import" href="../prefs/prefs.html">
 <link rel="import" href="../route.html">
@@ skipping 34 matching lines @@
               <div>$i18n{internetAddConnection}</div>
             </div>
             <cr-expand-button alt="$i18n{internetAddConnectionExpandA11yLabel}"
                 id="expandAddConnections" expanded="{{addConnectionExpanded_}}">
             </cr-expand-button>
           </div>
           <template is="dom-if" if="[[addConnectionExpanded_]]">
             <div actionable class="settings-box continuation center"
                 on-tap="onAddWiFiTap_">
               <div class="start add-no-icon">$i18n{internetAddWiFi}</div>
-              <button class="icon-external" is="paper-icon-button-light">
+              <button class="icon-external" is="paper-icon-button-light"
+                  aria-label="$i18n{internetAddWiFi}">
               </button>
             </div>
             <div actionable class="settings-box continuation center"
                 on-tap="onAddVPNTap_">
               <div class="start add-no-icon">$i18n{internetAddVPN}</div>
-              <button class="icon-external" is="paper-icon-button-light">
+              <button class="icon-external" is="paper-icon-button-light"
+                  aria-label="$i18n{internetAddVPN}">
               </button>
             </div>
             <template is="dom-repeat" items="[[thirdPartyVpnProviders_]]">
               <div actionable class="settings-box continuation center"
                   on-tap="onAddThirdPartyVpnTap_" provider="[[item]]">
                 <div class="start add-no-icon">
                   [[getAddThirdParrtyVpnLabel_(item)]]
                 </div>
               </div>
             </template>
@@ skipping 21 matching lines @@
               network-type="[[knownNetworksType_]]"
               on-show-detail="onShowDetail_"
               networking-private="[[networkingPrivate]]">
           </settings-internet-known-networks-page>
         </settings-subpage>
       </template>
     </settings-animated-pages>
   </template>
   <script src="internet_page.js"></script>
 </dom-module>