Mojo JS: Attempt to simplify bindTo* related code.

chrome/test/data/webui/plugins_browsertest.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.
 
 /**
  * @fileoverview Tests for chrome://plugins
  */
 
 /** @const {string} Path to source root. */
 var ROOT_PATH = '../../../../';
@@ skipping 40 matching lines @@
         'getPluginsData',
         'getShowDetails',
         'saveShowDetailsToPrefs',
       ]);
 
       /**
        * The data to be returned by |getPluginsData_|.
        * @private
        */
       this.pluginsData_ = [];
-
-      this.pageProxy = null;
     };
 
     TestBrowserProxy.prototype = {
       __proto__: settings.TestBrowserProxy.prototype,
 
       getPluginsData: function() {
         this.methodCalled('getPluginsData');
         return Promise.resolve({plugins: this.pluginsData_});
       },
 
@@ skipping 87 matching lines @@
         browserProxy.whenCalled('getShowDetails'),
       ]);
     });
 
     teardown(function() { browserProxy.reset(); });
 
     test('PluginsUpdated', function() {
       var plugins = document.querySelectorAll('.plugin');
       assertEquals(EXPECTED_PLUGINS, plugins.length);
 
-      pageProxy.onPluginsUpdated([fakePluginData]);
+      pageImpl.onPluginsUpdated([fakePluginData]);
       plugins = document.querySelectorAll('.plugin');
       assertEquals(1, plugins.length);
     });
 
     /**
      * Test that clicking on the +/- icons results in the expected calls to the
      * browser.
      */
     test('ToggleDetails', function() {
       var collapseEl = document.querySelector('#collapse');
@@ skipping 19 matching lines @@
             return browserProxy.whenCalled('saveShowDetailsToPrefs');
           }).then(function(expanded) {
             assertFalse(Boolean(expanded));
           });
     });
   });
 
   // Run all registered tests.
   mocha.run();
 });