WebUI: Move test_browser_proxy.js one level up.

chrome/test/data/webui/settings/startup_urls_page_test.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.
 
 cr.define('settings_startup_urls_page', function() {
   /**
    * @constructor
    * @implements {settings.StartupUrlsPageBrowserProxy}
-   * @extends {settings.TestBrowserProxy}
+   * @extends {TestBrowserProxy}
    */
   function TestStartupUrlsPageBrowserProxy() {
-    settings.TestBrowserProxy.call(this, [
+    TestBrowserProxy.call(this, [
       'addStartupPage',
       'editStartupPage',
       'loadStartupPages',
       'removeStartupPage',
       'useCurrentPages',
       'validateStartupPage',
     ]);
 
     /** @private {boolean} */
     this.urlIsValid_ = true;
   }
 
   TestStartupUrlsPageBrowserProxy.prototype = {
-    __proto__: settings.TestBrowserProxy.prototype,
+    __proto__: TestBrowserProxy.prototype,
 
     /** @param {boolean} isValid */
     setUrlValidity: function(isValid) {
       this.urlIsValid_ = isValid;
     },
 
     /** @override */
     addStartupPage: function(url) {
       this.methodCalled('addStartupPage', url);
       return Promise.resolve(this.urlIsValid_);
@@ skipping 318 matching lines @@
     test('Editable', function() {
       assertFalse(!!element.editable);
       assertFalse(!!element.$$('#dots'));
 
       element.editable = true;
       Polymer.dom.flush();
       assertTrue(!!element.$$('#dots'));
     });
   });
 });