content.js

document.addEventListener('contextmenu', function (e) {
    var port = chrome.extension.connect();
    var type = 'default';
    if (e.target.tagName == 'A'){
        type = 'link';
    }
    var url = e.target.href || '';
    port.postMessage({
        message : 'create_context_menu',
        data:{
            type : type,
            url : url
        }
    });
});