Examine source code of Click-jacking

{
  "manifest_version": 2,
  "name": "Click-jacking",
  "version": "1.0",
  "description": "Adds a red border to all webpages vulnerable to click-jacking",
  "icons": {
    "96": "icons/click-jacking.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "click-jacking.js"
      ]
    }
  ]
}