Examine source code of Fingerprint Spoofing

{
  "name": "Fingerprint Spoofing",
  "description": "Modify your broswer fingerprint!",
  "version": "1.3.4",
  "manifest_version": 2,
  "author": "doext",
  "homepage_url": "https://doext.github.io/fps",
  "content_scripts": [
    {
      "all_frames": true,
      "matches": [
        "*://*/*"
      ],
      "run_at": "document_start",
      "js": [
        "cts.js"
      ]
    }
  ],
  "permissions": [
    "storage",
    "privacy",
    "webRequest",
    "webRequestBlocking",
    "<all_urls>"
  ],
  "web_accessible_resources": [
    "cts.js"
  ],
  "icons": {
    "16": "icons/16.png",
    "32": "icons/32.png",
    "48": "icons/48.png",
    "128": "icons/128.png"
  },
  "browser_action": {
    "default_icon": {
      "16": "icons/16.png",
      "32": "icons/32.png",
      "64": "icons/64.png"
    },
    "default_popup": "setting.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "fps@doext"
    }
  }
}