Use mojo from the PDF extension instead of using an extension API.

extensions/test/data/keep_alive_client_unittest.js

-// Copyright 2014 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.
-
-/**
- * Unit tests for the keep-alive client.
- *
- * They are launched by extensions/renderer/mojo/keep_alive_client_unittest.cc.
- */
-
-var test = require('test').binding;
-var unittestBindings = require('test_environment_specific_bindings');
-var utils = require('utils');
-
-var shouldSucceed;
-
-// We need to set custom bindings for a real API and serial.getDevices has a
-// simple signature.
-var binding = require('binding').Binding.create('serial');
-binding.registerCustomHook(function(bindingsAPI) {
-  bindingsAPI.apiFunctions.setHandleRequestWithPromise('getDevices',
-      function() {
-    if (shouldSucceed)
-      return Promise.resolve([]);
-    else
-      return Promise.reject();
-  });
-});
-var apiFunction = binding.generate().getDevices;
-
-unittestBindings.exportTests([
-  // Test that a keep alive is created and destroyed for a successful API call.
-  function testKeepAliveWithSuccessfulCall() {
-    shouldSucceed = true;
-    utils.promise(apiFunction).then(test.succeed, test.fail);
-  },
-
-  // Test that a keep alive is created and destroyed for an unsuccessful API
-  // call.
-  function testKeepAliveWithError() {
-    shouldSucceed = false;
-    utils.promise(apiFunction).then(test.fail, test.succeed);
-  },
-], test.runTests, exports);