Examine source code of Extension Directe

{
  "name": "Extension Directe",
  "description": "Donne les moyennes sur ED",
  "version": "1.1",
  "manifest_version": 2,
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "/images/icon_16.png",
      "32": "/images/icon_32.png",
      "48": "/images/icon_48.png",
      "128": "/images/icon_128.png"
    }
  },
  "permissions": [
    "activeTab",
    "*://*/"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{0dbeba14-c290-4bb9-a35e-a16e23307a02}"
    }
  }
}