[MD settings] change icon on sync settings row

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

 <link rel="import" href="chrome://resources/cr_elements/icons.html">
 <link rel="import" href="chrome://resources/html/i18n_behavior.html">
 <link rel="import" href="chrome://resources/html/icon.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/neon-animation/neon-animatable.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-icon-button/paper-icon-button-light.html">
 <link rel="import" href="chrome://resources/cr_elements/cr_dialog/cr_dialog.html">
@@ skipping 138 matching lines @@
             <div class="middle">
               <div>$i18n{sync}</div>
               <div class="secondary" hidden="[[syncStatus.hasError]]">
                 [[syncStatus.statusText]]
               </div>
               <div class="secondary sync-error"
                   hidden="[[!syncStatus.hasError]]">
                 [[syncStatus.statusText]]
               </div>
             </div>
-          <button class="icon-external" is="paper-icon-button-light"></button>
+            <button class="icon-arrow-right" is="paper-icon-button-light"></button>
           </div>
         </template>
 
         <div class="settings-box two-line" id="activity-controls"
             on-tap="onActivityControlsTap_" actionable
             hidden="[[!syncStatus.signedIn]]">
           <div class="icon-container">
             <div id="googleg-logo"></div>
           </div>
           <div class="middle">
@@ skipping 166 matching lines @@
 
 <if expr="chromeos">
     <template is="dom-if" if="[[easyUnlockEnabled_]]">
       <easy-unlock-turn-off-dialog id="easyUnlockTurnOffDialog">
       </easy-unlock-turn-off-dialog>
     </template>
 </if>
   </template>
   <script src="people_page.js"></script>
 </dom-module>