Examine source code of menu search google

{
  "manifest_version": 2,
  "name": "menu search google",
  "version": "0.1",
  "description": "A menu option to search selected text on google, by yun.",
  "icons": {
    "16": "icons/google.png"
  },
  "permissions": [
    "contextMenus"
  ],
  "background": {
    "scripts": [
      "search.js"
    ]
  }
}