Mojo JS: Attempt to simplify bindTo* related code.

chrome/browser/resources/plugins.js

Index: chrome/browser/resources/plugins.js
diff --git a/chrome/browser/resources/plugins.js b/chrome/browser/resources/plugins.js
index 19b21195729468df0efb39fc1a3728846e35bae2..05e13897d869701a02cae1e9aa903362641f05a6 100644
--- a/chrome/browser/resources/plugins.js
+++ b/chrome/browser/resources/plugins.js
@@ -263,48 +263,43 @@ function importModules(moduleNames) {
   });
 }
 
-// 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);
   });
 }