Examine source code of sp Content setting

{
  "name": "sp Content settings",
  "version": "2.1",
  "description": "Shows the content settings for the current site.",
  "permissions": [
    "contentSettings",
    "tabs"
  ],
  "browser_action": {
    "default_icon": "contentSettings.png",
    "default_popup": "popup.html"
  },
  "manifest_version": 2
}