Add a Javascript wrapper around ServiceRegistry and expose it to WebUI.

content/test/data/web_ui_mojo.js

 // Copyright 2014 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.
 
 define('main', [
     'mojo/public/js/bindings/connection',
     'content/test/data/web_ui_test_mojo_bindings.mojom',
-], function (connection, bindings) {
+    'content/public/renderer/service_registry',
+], function (connection, bindings, serviceRegistry) {
   var retainedConnection;
 
   function RendererTargetTest(bindings) {
     this.bindings_ = bindings;
   }
 
   // TODO(aa): It is a bummer to need this stub object in JavaScript. We should
   // have a 'client' object that contains both the sending and receiving bits of
   // the client side of the interface. Since JS is loosely typed, we do not need
   // a separate base class to inherit from to receive callbacks.
   RendererTargetTest.prototype =
       Object.create(bindings.RendererTargetStub.prototype);
 
   RendererTargetTest.prototype.ping = function () {
     this.bindings_.pingResponse();
   };
 
-  return function(handle) {
+  return function() {
     retainedConnection = new connection.Connection(
-        handle, RendererTargetTest, bindings.BrowserTargetProxy);
+        serviceRegistry.getInterface(bindings.BrowserTargetProxy.NAME_),

[darin (slow to review), 2014/06/21 04:44:16]

same nit about having to use NAME_ here. maybe there should just be a TODO in
this CL about figuring out a better solution.

[Sam McNally, 2014/06/24 08:45:01]

Done.

+        RendererTargetTest,
+        bindings.BrowserTargetProxy);
   };
 });