Removing chrome.pushMessaging API

chrome/test/data/extensions/api_test/push_messaging/event_dispatch.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.
-
-function verifyDetails(details) {
-  chrome.test.assertEq(1, details.subchannelId);
-  chrome.test.assertEq('payload', details.payload);
-}
-
-function testEventDispatch() {
-  chrome.pushMessaging.onMessage.addListener(
-      chrome.test.callbackPass(verifyDetails));
-}
-
-chrome.test.runTests([testEventDispatch]);