Mojo JS: Attempt to simplify bindTo* related code.

chrome/browser/resources/plugins.js

 // Copyright (c) 2012 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.
 
 /**
  * Takes the |pluginsData| input argument which represents data about the
  * currently installed/running plugins and populates the html jstemplate with
  * that data.
  * @param {Object} pluginsData Detailed info about installed plugins. Same
  *     expected format as returnPluginsData().
@@ skipping 245 matching lines @@
  * @return {!Promise}
  */
 function importModules(moduleNames) {
   return new Promise(function(resolve, reject) {
     define(moduleNames, function(var_args) {
       resolve(Array.prototype.slice.call(arguments, 0));
     });
   });
 }
 
-// NOTE: Need to keep a reference to the stub here such that it is not garbage
-// collected, which causes the pipe to close and future calls from C++ to JS to
-// get dropped.
-var pluginsPageStub = null;
-
+// NOTE: Need to keep a global reference to the |pageImpl| such that it is not
+// garbage collected, which causes the pipe to close and future calls from C++
+// to JS to get dropped. This also allows tests to make direct calls on it.
+var pageImpl = null;
 var browserProxy = null;
-// Exposed globally such that the tests can make direct calls on it.
-var pageProxy = null;
 
 function initializeProxies() {
   return importModules([
-    'mojo/public/js/bindings',
-    'mojo/public/js/core',
     'mojo/public/js/connection',
     'chrome/browser/ui/webui/plugins/plugins.mojom',
     'content/public/renderer/frame_service_registry',
   ]).then(function(modules) {
-    var bindings = modules[0];
-    var core = modules[1];
-    var connection = modules[2];
-    var pluginsMojom = modules[3];
-    var serviceProvider = modules[4];
+    var connection = modules[0];
+    var pluginsMojom = modules[1];
+    var serviceRegistry = modules[2];
 
     browserProxy = connection.bindHandleToProxy(
-        serviceProvider.connectToService(pluginsMojom.PluginsPageHandler.name),
+        serviceRegistry.connectToService(pluginsMojom.PluginsPageHandler.name),
         pluginsMojom.PluginsPageHandler);
 
-    // Connect pipe handle to JS code.
-    var pipe = core.createMessagePipe();
-    pluginsPageStub = connection.bindHandleToStub(
-        pipe.handle0, pluginsMojom.PluginsPage);
+    /** @constructor */
+    var PluginsPageImpl = function() {};
 
-    pageProxy = {
+    PluginsPageImpl.prototype = {
       __proto__: pluginsMojom.PluginsPage.stubClass.prototype,
+
+      /** @override */
       onPluginsUpdated: function(plugins) {
         returnPluginsData({plugins: plugins});
       },
     };
+    pageImpl = new PluginsPageImpl();
 
-    bindings.StubBindings(pluginsPageStub).delegate = pageProxy;
-    // Send pipe handle to C++.
-    browserProxy.setClientPage(pipe.handle1);
+    // Create a message pipe, with one end of the pipe already connected to JS.
+    var handle = connection.bindStubDerivedImpl(pageImpl);
+    // Send the other end of the pipe to C++.
+    browserProxy.setClientPage(handle);
   });
 }
 
 /**
  * Overriden by tests to give them a chance to setup a fake Mojo browser proxy
  * before any other code executes.
  * @return {!Promise} A promise firing once necessary setup has been completed.
  */
 var setupFn = setupFn || function() { return Promise.resolve(); };
 
@@ skipping 16 matching lines @@
 
     // Unfortunately, we don't have notifications for plugin (list) status
     // changes (yet), so in the meanwhile just update regularly.
     setInterval(function() {
       browserProxy.getPluginsData().then(returnPluginsData);
     }, 30000);
   });
 }
 
 document.addEventListener('DOMContentLoaded', main);