Examine source code of Show/Hide passwords

{
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "description": "Add a link in web pages to show and hide passwords",
  "developer": {
    "name": "Didier Lafleur"
  },
  "manifest_version": 2,
  "name": "Show/Hide passwords",
  "version": "0.4",
  "icons": {
    "128": "icon128.png"
  }
}