[i18n] browser help, i18n-content to $i18n{}

chrome/browser/resources/help/channel_change_page.html

 <div id="channel-change-page" class="page" hidden>
   <div class="close-button"></div>
-  <h1 i18n-content="channelChangePageTitle"></h1>
+  <h1>$i18n{channelChangePageTitle}</h1>
   <div class="content-area">
     <div class="channel-change-page-channel radio">
       <input id="channel-change-page-stable-option"
           type="radio" name="channel" value="stable-channel">
-      <label for="channel-change-page-stable-option" i18n-content="stable">
-      </label>
+      <label for="channel-change-page-stable-option">$i18n{stable}</label>
     </div>
     <div class="channel-change-page-channel radio">
       <input id="channel-change-page-beta-option"
           type="radio" name="channel" value="beta-channel">
-      <label for="channel-change-page-beta-option" i18n-content="beta"></label>
+      <label for="channel-change-page-beta-option">$i18n{beta}</label>
     </div>
     <div class="channel-change-page-channel radio">
       <input id="channel-change-page-dev-option"
           type="radio" name="channel" value="dev-channel">
-      <label for="channel-change-page-dev-option" i18n-content="dev"></label>
+      <label for="channel-change-page-dev-option">$i18n{dev}</label>
     </div>
   </div>
   <div class="content-area">
     <div class="show-when-selected-channel-requires-powerwash">
-      <h2 i18n-content="channelChangePagePowerwashTitle"></h2>
-      <div i18n-content="channelChangePagePowerwashMessage"></div>
+      <h2>$i18n{channelChangePagePowerwashTitle}</h2>
+      <div>$i18n{channelChangePagePowerwashMessage}</div>
     </div>
     <div class="show-when-selected-channel-requires-delayed-update">
-      <h2 i18n-content="channelChangePageDelayedChangeTitle"></h2>
-      <div i18n-content="channelChangePageDelayedChangeMessage"></div>
+      <h2>$i18n{channelChangePageDelayedChangeTitle}</h2>
+      <div>$i18n{channelChangePageDelayedChangeMessage}</div>
     </div>
     <div class="show-when-selected-channel-unstable">
-      <h2 i18n-content="channelChangePageUnstableTitle"></h2>
-      <div i18n-content="channelChangePageUnstableMessage"></div>
+      <h2>$i18n{channelChangePageUnstableTitle}</h2>
+      <div>$i18n{channelChangePageUnstableMessage}</div>
     </div>
   </div>
   <div class="action-area">
     <div class="button-strip">
       <button id="channel-change-page-powerwash-button"
-          class="show-when-selected-channel-requires-powerwash"
-          i18n-content="channelChangePagePowerwashButton">
+          class="show-when-selected-channel-requires-powerwash">
+        $i18n{channelChangePagePowerwashButton}
       </button>
       <button id="channel-change-page-change-button"
           class="show-when-selected-channel-requires-delayed-update
                  show-when-selected-channel-good
-                 show-when-selected-channel-unstable"
-          i18n-content="channelChangePageChangeButton">
+                 show-when-selected-channel-unstable">
+        $i18n{channelChangePageChangeButton}
       </button>
-      <button id="channel-change-page-cancel-button"
-          class="default-button"
-          i18n-content="channelChangePageCancelButton">
+      <button id="channel-change-page-cancel-button" class="default-button">
+        $i18n{channelChangePageCancelButton}
       </button>
     </div>
   </div>
 </div>