Examine source code of Google Black Glass

{
  "manifest_version": 3,
  "name": "Google Black Glass",
  "version": "0.9",
  "description": "AMOLED black Google theme with frosted-glass search bar.",
  "icons": {
    "48": "icons/icon48.png",
    "96": "icons/icon96.png",
    "128": "icons/icon128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.google.com/*"
      ],
      "css": [
        "content.css"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "ggt@toast1599",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  }
}