Removing chrome.pushMessaging API

chrome/test/data/extensions/background_app/background.js

 // Copyright 2013 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.
 
 // This is a minimal sample of a Apps V2 app with background permission.
 //
 // This function gets called in the packaged app model on launch.
 chrome.app.runtime.onLaunched.addListener(function() {
   console.log("Background App Launched!");
 
   // We'll set up push messaging so we have something to keep the background
   // app registered.
   setupPush();
 });
 
 // This function gets called in the packaged app model on install.
 chrome.runtime.onInstalled.addListener(function() {
   console.log("Background App installed!");
 });
 
 // This function gets called in the packaged app model on shutdown.
 chrome.runtime.onSuspend.addListener(function() {
   console.log("Background App shutting down");
 });
-
-// Register for push messages.
-// This should be called every time the Push Messaging App starts up.
-function setupPush() {
-  chrome.pushMessaging.onMessage.addListener(messageCallback);
-
-  // Ensure that adding the listener took effect.
-  var listeners = chrome.pushMessaging.onMessage.hasListeners();
-  console.log('registered listener for push messages ' + listeners);
-}
-
-// This callback receives the pushed message from the push server.
-function messageCallback(message) {
-  console.log("push messaging callback seen");
-}