Examine source code of au-revoir-utm

{
  "manifest_version": 2,
  "name": "au-revoir-utm",
  "version": "1.1.1resigned1",
  "description": "Removes crappy utm_ tracking stuff",
  "homepage_url": "http://github.com/rik/au-revoir-utm",
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "utm.js",
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "jid1-yRtlFKrTMBrAtQ@jetpack"
    }
  }
}