contextMenus

manifest.json:
  {
    "name": "P",
    "version": "1.0",
    "description": "P",

    "permissions": [
	    "contextMenus"
    ],
    "background": {
	    "scripts": ["background.js"],
	    "persistent": false
    },
    "manifest_version": 2
  }


background.js:
function genericOnClick(info, tab) {
  console.log("item " + info.menuItemId + " was clicked");
  console.log("info: " + JSON.stringify(info));
  console.log("tab: " + JSON.stringify(tab));
}

chrome.runtime.onInstalled.addListener(function() {
	chrome.contextMenus.create({
		"id": "sampleContextMenu",
		"title": "Sample Context Menu",
		"contexts": ["all"]
	});
	console.log("created context menu");
	chrome.contextMenus.onClicked.addListener(function(info, tab) {
		if (info.menuItemId == "sampleContextMenu") {
			alert("bla bla bla");
			console.log("menu item was clicked");
		}
	});
});