Examine source code of Patch Viewer

{
  "manifest_version": 2,
  "name": "Patch Viewer",
  "version": "0.1.0",
  "description": "Add a link to the raw patch view on GitHub commit pages",
  "content_scripts": [
    {
      "matches": [
        "*://github.com/*/*/commit/*"
      ],
      "js": [
        "patch-viewer.js"
      ]
    }
  ]
}