Remove the notificationProvider extension API

chrome/test/data/extensions/api_test/notification_provider/events/test.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.
-
-var idString = "id1";
-
-function testOnCreated() {
-
-  var content = {
-    type: "basic",
-    iconUrl: "icon.png",
-    title: "Title",
-    message: "This is the message."
-  };
-
-  var createCallback = function (id) {}
-  chrome.notifications.create(idString, content, createCallback);
-
-  chrome.notificationProvider.onCreated.addListener(function(senderId,
-                                                             notificationId,
-                                                             options) {
-    var str = notificationId.split("-");
-    chrome.test.assertEq(idString, str[1]);
-    chrome.test.assertEq(options.title, content.title);
-    chrome.test.assertEq(options.message, content.message);
-    chrome.test.succeed();
-  });
-};
-
-chrome.test.runTests([ testOnCreated ]);