Examine source code of Github Light Favicon

{
  "manifest_version": 2,
  "name": "Github Light Favicon",
  "version": "1.1",
  "description": "Changes Github's favicon to be white.",
  "icons": {},
  "content_scripts": [
    {
      "matches": [
        "*://*.github.com/*"
      ],
      "js": [
        "github-light-favicon.js"
      ]
    }
  ]
}