Examine source code of Video Speed Controller

{
  "manifest_version": 2,
  "name": "Video Speed Controller",
  "version": "1.0",
  "description": "Adjust playback speed of HTML5 videos on any website.",
  "icons": {
    "48": "icon.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "style.css"
      ],
      "run_at": "document_idle"
    }
  ],
  "permissions": [
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{a4d1ff88-333c-438a-8915-7c62301c7495}"
    }
  }
}