Remove Chromecast extension support from cast system tray menu.

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

-// Copyright (c) 2015 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 backgroundSetup = {}
-
-// If all required activity information is available, then this will return an
-// activity structure; otherwise, it will return null. This lets us
-// unconditionally assign to the 'activity' field in a JSON object.
-tryCreateActivity_ = function(id, title, tabId) {
-  if (id === undefined || title === undefined || tabId === undefined)
-    return null;
-
-  return {
-    'id': id,
-    'title': title,
-    'tabId': tabId
-  };
-}
-
-var receiversActivities = [];
-var sendDevices = function() {
-  chrome.cast.devicesPrivate.updateDevices(receiversActivities);
-}
-chrome.cast.devicesPrivate.updateDevicesRequested.addListener(sendDevices);
-
-// Add a new receiver. |activityTitle| and |activityTabId| are optional
-// parameters.
-var addReceiver = function(id, receiverName, activityTitle, activityTabId) {
-  receiversActivities.push({
-    'receiver': {
-      'id': id,
-      'name': receiverName
-    },
-    'activity': tryCreateActivity_(id, activityTitle, activityTabId)
-  });
-
-  sendDevices();
-}
-
-var stopMirroringCalled = false;
-chrome.cast.devicesPrivate.stopCast.addListener(function(reason) {
-  if (reason !== 'user-stop')
-    throw 'expected reason to be "user-stop"';
-
-  var foundActivity = false;
-  for (item of receiversActivities) {
-    if (item.activity != null) {
-      item.activity = null;
-      foundActivity = true;
-    }
-  }
-  if (foundActivity === false)
-    throw 'stopMirroring called when there was nothing being mirrored'
-
-  stopMirroringCalled = true;
-  sendDevices();
-});
-
-
-var launchDesktopMirroringReceiverId = '';
-chrome.cast.devicesPrivate.startCast.addListener(function(receiverId) {
-  launchDesktopMirroringReceiverId = receiverId;
-
-  var tabTitle = 'Tab Title';
-  var tabId = 1;
-
-  for (item of receiversActivities) {
-    if (item.receiver.id == receiverId) {
-      item.activity = tryCreateActivity_(receiverId, tabTitle, tabId);
-      break;
-    }
-  }
-
-  sendDevices();
-});