chrome/common/extensions/docs/examples/api/preferences/allowThirdPartyCookies/manifest.json

{
  "name" : "Block/allow third-party cookies API example extension",
  "version" : "0.1",
  "description" : "Sample extension which demonstrates how to access a preference.",
  "permissions": [ "privacy" ],
  "browser_action": {
     "default_icon": "advicedog.jpg",
     "default_popup": "popup.html"
  },
  "manifest_version": 2
}