Examine source code of Reco - Screen Recorder

{
  "manifest_version": 2,
  "name": "Reco - Screen Recorder",
  "description": "Reco is screen, audio and camera recorder extension tool",
  "version": "2.1.2",
  "icons": {
    "32": "icons/32.png",
    "64": "icons/64.png",
    "128": "icons/128.png",
    "512": "icons/512.png"
  },
  "browser_action": {
    "default_title": "Reco - Screen Recorder",
    "default_popup": "popup.html"
  },
  "permissions": [
    "desktopCapture",
    "activeTab",
    "tabs",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "css": [
        "content.css"
      ],
      "js": [
        "content.js"
      ],
      "matches": [
        "*://*/*"
      ],
      "run_at": "document_end"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{ce1eeb6b-e71f-4f99-822f-221fb38be1a7}"
    }
  }
}