CX contextMenus Example

//background
chrome.runtime.onInstalled.addListener(function() {
    var context = "selection";
    var title = "Proceed to content";
    var id = chrome.contextMenus.create({
        "title": title,
        "contexts":[context],
        "id": "context" + context
    });
});

chrome.contextMenus.onClicked.addListener(onClickHandler);

function onClickHandler(info, tab) {
  var sText = info.selectionText;
  alert(sText);
};