Examine source code of Borderify

{
  "manifest_version": 2,
  "name": "Borderify",
  "version": "1.0",
  "description": "Adds a red border to all webpages matching mozilla.org.",
  "permissions": [
    "storage",
    "tabs",
    "http://*/*",
    "https://*/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "borderify.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{fac9de72-6e06-4b01-9bc1-2190875a78e8}"
    }
  }
}