Examine source code of Original Twitter Logo

{
  "manifest_version": 2,
  "name": "Custom Twitter Logo",
  "version": "1.1",
  "description": "Replace Twitter logo with a custom SVG.",
  "content_scripts": [
    {
      "matches": [
        "*://twitter.com/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{37a50b87-ec32-4bae-9447-1e1ada8d634d}"
    }
  }
}