Update app runtime custom bindings to handle no WebIntents launch data.

chrome/test/data/extensions/platform_apps/launch_reply/test.js

-// Copyright (c) 2012 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.
-
-chrome.app.runtime.onLaunched.addListener(function(launchData) {
-  // Test that there is a launchData.intent, and it is set up properly. Then
-  // immediately reply to the intent with a success message.
-  chrome.test.runTests([
-    function testIntent() {
-      chrome.test.assertFalse(!launchData, "No launchData");
-      chrome.test.assertFalse(!launchData.intent, "No launchData.intent");
-      launchData.intent.postResult(true);
-    }
-  ]);
-});