[i18n] chromeos login i18n-content to $i18n{}

chrome/browser/resources/chromeos/login/oobe_screen_user_image.html

 <div class="step right hidden loading no-logo" id="user-image" hidden>
   <div class="step-contents">
     <div id="user-image-screen-curtain">
-      <p id="user-image-screen-description"
-         i18n-content="userImageScreenDescription"></p>
+      <p id="user-image-screen-description">
+        $i18n{userImageScreenDescription}
+      </p>
     </div>
     <div id="user-image-screen-main">
       <grid id="user-image-grid" tabindex="1"
           aria-labelledby="user-image-screen-description">
       </grid>
       <div id="user-image-preview">
         <img id="user-image-preview-img" class="animated-transform" alt="">
         <div class="user-image-stream-area">
           <div class="perspective-box">
             <div id="user-image-stream-crop">
               <video class="user-image-stream" autoplay></video>
             </div>
           </div>
           <div class="spinner"></div>
         </div>
         <p id="user-image-preview-caption"></p>
         <button id="discard-photo" i18n-values="title:discardPhoto"
             tabindex="2"></button>
         <button id="take-photo" i18n-values="title:takePhoto" tabindex="2">
         </button>
         <button id="flip-photo" class="custom-appearance"
             i18n-values="title:flipPhoto" tabindex="1"></button>
       </div>
       <div id="user-image-attribution">
-        <span i18n-content="authorCredit"></span>
+        <span>$i18n{authorCredit}</span>
         <strong id="user-image-author-name"></strong>
         <a id="user-image-author-website" target="_blank"></a>
       </div>
     </div>
   </div>
   <div id="user-image-controls" class="step-controls"></div>
   <div id="user-images-loading" class="step-loading">
     <throbber-notice i18n-values="text:syncingPreferences" class="fit">
     </throbber-notice>
   </div>
 </div>