test.js

/**
 * initialization
 */
function initializeCastApi() {
    var sessionRequest = new chrome.cast.SessionRequest(applicationID);
    var apiConfig = new chrome.cast.ApiConfig(sessionRequest,sessionListener,receiverListener);
    chrome.cast.initialize(apiConfig, onInitSuccess, onError);
};

/**
 * initialization success callback
 */
function onInitSuccess() {
  appendMessage("init success");
}