Chrome Extension Cookies

Question

I try get cookie from page with extension but when i write console.log(chrome) return object but cookies key not exist This is my manifest json

{
  "name": "Call Center",
  "manifest_version": 2,
  "version": "1.0",
  "description": "Extension For Call Center",
  "permissions": [
    "cookies",
    "*://*.youtube.com/*"
  ],
  "content_scripts": [
    {
      "matches": ["*://*.youtube.com/*"],
      "js": ["script.js"]
    }
  ],
  "web_accessible_resources": ["script.js","hello.js"]
}