Adding a "Learn more" link to the Google DNS selection

chrome/browser/resources/options/chromeos/internet_detail.html

 <div id="details-internet-page" class="page" hidden>
   <div class="close-button"></div>
   <!-- Network header -->
   <div id="network-details-header">
     <div id="network-details-title"></div>
     <div id="network-details-subtitle">
       <span id="network-details-subtitle-status"></span>
       <span id="network-details-subtitle-separator"> - </span>
       <span id="network-details-subtitle-type"></span>
     </div>
@@ skipping 448 matching lines @@
             <input id="automatic-dns-radio" type="radio" name="dnstype"
                 value="automatic">
             <span i18n-content="automaticNameServers"></span>
           </label>
         </div>
         <div id="automatic-dns-display" class="dns-display"></div>
         <div class="radio">
           <label>
             <input id="google-dns-radio" type="radio" name="dnstype"
                 value="google">
-            <span i18n-content="googleNameServers"></span>
+            <span id="google-dns-label"></span>
           </label>
         </div>
         <div id="google-dns-display" class="dns-display"></div>
         <div class="radio">
           <label>
             <input id="user-dns-radio" type="radio" name="dnstype"
                 value="user">
             <span i18n-content="userNameServers"></span>
           </label>
         </div>
@@ skipping 200 matching lines @@
       </button>
       <button id="details-internet-disconnect" i18n-content="disconnectButton">
       </button>
       <button id="activate-details" i18n-content="activateButton"></button>
       <button id="buyplan-details" i18n-content="buyplanButton"></button>
       <button id="view-account-details" i18n-content="viewAccountButton">
       </button>
     </div>
   </div>
 </div>