WebUI: Move test_browser_proxy.js one level up.

chrome/test/data/webui/settings/downloads_page_test.js

 // Copyright 2017 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.
 
 /**
  * @constructor
  * @implements {settings.DownloadsBrowserProxy}
- * @extends {settings.TestBrowserProxy}
+ * @extends {TestBrowserProxy}
  */
 var TestDownloadsBrowserProxy = function() {
-  settings.TestBrowserProxy.call(this, [
+  TestBrowserProxy.call(this, [
     'initializeDownloads',
     'selectDownloadLocation',
     'resetAutoOpenFileTypes',
   ]);
 };
 
 TestDownloadsBrowserProxy.prototype = {
-  __proto__: settings.TestBrowserProxy.prototype,
+  __proto__: TestBrowserProxy.prototype,
 
   /** @override */
   initializeDownloads: function() {
     this.methodCalled('initializeDownloads');
   },
 
   /** @override */
   selectDownloadLocation: function() {
     this.methodCalled('selectDownloadLocation');
   },
@@ skipping 47 matching lines @@
     MockInteractions.tap(button);
     return DownloadsBrowserProxy.whenCalled('resetAutoOpenFileTypes')
         .then(function() {
           cr.webUIListenerCallback('auto-open-downloads-changed', false);
           Polymer.dom.flush();
           var button = downloadsPage.$$('#resetAutoOpenFileTypes');
           assertTrue(!button);
         });
   });
 });