onUpdated.js

    chrome.tabs.onUpdated.addListener(function(tabId, details, tab) {
        if (details.status === 'loading' && details.url === 'https://soundcloud.com/stream'){
            execute = true;
        }

        if (tab.url === "https://soundcloud.com/stream" && tab.status === "complete" && execute === true) {
            execute = false;
            chrome.tabs.executeScript(tabId, {
                 file: "js/scripts/streamContent.js"
             }, function (res) {console.log(res);});
        }

     });