WebUI: Move test_browser_proxy.js one level up.

chrome/test/data/webui/print_preview/native_layer_stub.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.
 
 cr.define('print_preview', function() {
   /**
   * Test version of the native layer.
   * @constructor
-  * @extends {settings.TestBrowserProxy}
+  * @extends {test.TestBrowserProxy}
   */
   function NativeLayerStub() {
-    settings.TestBrowserProxy.call(this, [
+    test.TestBrowserProxy.call(this, [
         'getInitialSettings', 'getPrinters', 'setupPrinter' ]);
 
     /**
      * @private {!cr.EventTarget} The event target used for dispatching and
      *     receiving events.
      */
     this.eventTarget_ = new cr.EventTarget();
 
     /** @private {boolean} Whether the native layer has sent a print message. */
     this.printStarted_ = false;
@@ skipping 35 matching lines @@
     this.destinationToWatch_ = '';
 
     /**
      * @private {number} The number of calls to
      *     |getLocalDestinationCapabilities| with id = |destinationToWatch_|.
      */
     this.getLocalDestinationCapabilitiesCallCount_ = 0;
   }
 
   NativeLayerStub.prototype = {
-    __proto__: settings.TestBrowserProxy.prototype,
+    __proto__: test.TestBrowserProxy.prototype,
 
     /** @override */
     getInitialSettings: function() {
       this.methodCalled('getInitialSettings');
       return Promise.resolve(this.initialSettings_);
     },
 
     /** @override */
     getPrinters: function() {
       this.methodCalled('getPrinters');
@@ skipping 81 matching lines @@
     setSetupPrinterResponse: function(reject, response) {
       this.shouldRejectPrinterSetup_ = reject;
       this.setupPrinterResponse_ = response;
     },
   };
 
   return {
     NativeLayerStub: NativeLayerStub,
   };
 });