Examine source code of Websockets URL Sender

{
  "manifest_version": 2,
  "name": "WebsocketsURLSender",
  "version": "0.2",
  "description": "Sends the URL of the website you are visiting via websockets.",
  "icons": {
    "48": "icons/icon-48.png",
    "567": "icons/icon-567.png"
  },
  "browser_action": {
    "default_popup": "popup/popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "WebsocketsURLSender.js"
      ]
    }
  ]
}