MD Settings: clicking on the "Learn more" shouldn't select the sync passphrase option

chrome/browser/resources/settings/people_page/sync_page.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/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/paper-checkbox/paper-checkbox.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-input/paper-input.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-radio-button/paper-radio-button.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-radio-group/paper-radio-group.html">
 <link rel="import" href="/people_page/sync_browser_proxy.html">
 <link rel="import" href="/route.html">
@@ skipping 210 matching lines @@
             </paper-button>
           </div>
         </div>
       </template>
 
       <template is="dom-if" if="[[syncPrefs.passphraseRequired]]">
         <div class="list-frame">
           <div class="list-item">
             <span>
               [[enterPassphrasePrompt_(syncPrefs.passphraseTypeIsCustom)]]
-              <a href="$i18nRaw{syncErrorHelpUrl}" target="_blank">
+              <a href="$i18nRaw{syncErrorHelpUrl}" target="_blank"
+                  on-tap="onSyncLearnMoreTap_">
                 $i18n{learnMore}
               </a>
             </span>
           </div>
           <div id="existingPassphraseContainer" class="list-item">
             <paper-input id="existingPassphraseInput" type="password"
                 value="{{existingPassphrase_}}"
                 placeholder="$i18n{passphrasePlaceholder}"
                 error-message="$i18n{incorrectPassphraseError}">
             </paper-input>
             <paper-button id="submitExistingPassphrase"
                 on-tap="onSubmitExistingPassphraseTap_" class="action-button"
                 disabled="[[!existingPassphrase_]]">
               $i18n{submitPassphraseButton}
             </paper-button>
           </div>
           <div id="passphraseRecoverHint" class="list-item">
             <span>$i18nRaw{passphraseRecover}</span>
           </div>
         </div>
       </template>
     </div>
   </template>
   <script src="sync_page.js"></script>
 </dom-module>