Run clang-format on .js files in c/b/r/md_extensions

chrome/browser/resources/md_extensions/extensions.js

 // Copyright 2016 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.
 
 (function() {
-  'use strict';
-  var manager = /** @type {extensions.Manager} */(
-                    document.querySelector('extensions-manager'));
-  manager.readyPromiseResolver.promise.then(function() {
-    extensions.Service.getInstance().managerReady(manager);
-  });
+'use strict';
+var manager = /** @type {extensions.Manager} */ (
+    document.querySelector('extensions-manager'));
+manager.readyPromiseResolver.promise.then(function() {
+  extensions.Service.getInstance().managerReady(manager);
+});
 })();