WebUI: Move test_browser_proxy.js one level up.

chrome/test/data/webui/settings/test_extension_control_browser_proxy.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.
 
 /**
  * @constructor
  * @implements {settings.ExtensionControlBrowserProxy}
- * @extends {settings.TestBrowserProxy}
+ * @extends {TestBrowserProxy}
  */
 function TestExtensionControlBrowserProxy() {
-  settings.TestBrowserProxy.call(this, [
+  TestBrowserProxy.call(this, [
     'disableExtension',
     'manageExtension',
   ]);
 }
 
 TestExtensionControlBrowserProxy.prototype = {
-  __proto__: settings.TestBrowserProxy.prototype,
+  __proto__: TestBrowserProxy.prototype,
 
   /** @override */
   disableExtension: function(extensionId) {
     this.methodCalled('disableExtension', extensionId);
   },
 
   /** @override */
   manageExtension: function(extensionId) {
     this.methodCalled('manageExtension', extensionId);
   },
 };