Mojo-ifying chrome://version.

components/version_ui/resources/about_version.js

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-/**
- * Callback from the backend with the list of variations to display.
- * This call will build the variations section of the version page, or hide that
- * section if there are none to display.
- * @param {!Array<string>} variationsList The list of variations.
- */
-function returnVariationInfo(variationsList) {
-  $('variations-section').hidden = !variationsList.length;
-  $('variations-list').appendChild(
-      parseHtmlSubset(variationsList.join('<br>'), ['BR']));
+/** @return {!Promise} */
+function getUiHandler() {
+  return new Promise(function(resolve, reject) {
+    define([
+      'mojo/public/js/connection',
+      'components/version_ui/version.mojom',
+      'content/public/renderer/frame_service_registry',
+    ], function(connection, versionMojom, serviceRegistry) {
+      var uiHandler = connection.bindHandleToProxy(
+          serviceRegistry.connectToService(
+              versionMojom.VersionPageHandler.name),
+          versionMojom.VersionPageHandler);
+      resolve(uiHandler);
+    });
+  });
 }
 
 /**
- * Callback from the backend with the executable and profile paths to display.
- * @param {string} execPath The executable path to display.
- * @param {string} profilePath The profile path to display.
+ * @return {!Promise} Fires when DOMContentLoaded event is received.
  */
-function returnFilePaths(execPath, profilePath) {
-  $('executable_path').textContent = execPath;
-  $('profile_path').textContent = profilePath;
+function whenDomContentLoaded() {
+  return new Promise(function(resolve, reject) {
+    document.addEventListener('DOMContentLoaded', resolve);
+  });
 }
 
-/**
- * Callback from the backend with the Flash version to display.
- * @param {string} flashVersion The Flash version to display.
- */
-function returnFlashVersion(flashVersion) {
-  $('flash_version').textContent = flashVersion;
+function main() {
+  Promise.all([
+    whenDomContentLoaded(), getUiHandler()
+  ]).then(function(results) {
+    var uiHandler = results[1];
+    uiHandler.getFilePaths().then(function(response) {
+      $('executable_path').textContent = response.execPath;
+      $('profile_path').textContent = response.profilePath;
+    });
+    uiHandler.getVariations().then(function(response) {
+      $('variations-section').hidden = response.variations.length == 0;
+      $('variations-list').appendChild(
+          parseHtmlSubset(response.variations.join('<br>'), ['BR']));
+    });
+
+    if (!cr.isAndroid) {
+      uiHandler.getFlashVersion().then(function(response) {
+        $('flash_version').textContent = response.flashVersion;
+      });
+    }
+
+    if (cr.isChromeOS) {
+      uiHandler.getOsVersion().then(function(response) {
+        $('os_version').textContent = response.osVersion;
+      });
+      uiHandler.getArcVersion().then(function(response) {
+        $('arc_version').textContent = response.arcVersion;
+        $('arc_holder').hidden = !response.arcVersion;
+      });
+    }
+  });
 }
-
-/**
- * Callback from the backend with the OS version to display.
- * @param {string} osVersion The OS version to display.
- */
-function returnOsVersion(osVersion) {
-  $('os_version').textContent = osVersion;
-}
-
-
-/**
- * Callback from the backend with the ARC version to display.
- * @param {string} arcVersion The ARC version to display.
- */
-function returnARCVersion(arcVersion) {
-  $('arc_version').textContent = arcVersion;
-  $('arc_holder').hidden = !arcVersion;
-}
-
-/* All the work we do onload. */
-function onLoadWork() {
-  chrome.send('requestVersionInfo');
-  $('arc_holder').hidden = true;
-}
-
-document.addEventListener('DOMContentLoaded', onLoadWork);
+main();