Examine source code of dspace.chat

{
  "manifest_version": 2,
  "name": "D-space Ext",
  "version": "1.1",
  "description": "Adds a chat area for chatting with other people on the same website.",
  "icons": {
    "48": "icons/icon2.png"
  },
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "*://news.ycombinator.com/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "content_scripts": [
    {
      "matches": [
        "*://news.ycombinator.com/*",
        "*://*.reddit.com/*",
        "*://*.techmeme.com/*",
        "*://dspace.chat/*"
      ],
      "js": [
        "dspace.js"
      ],
      "css": [
        "dspace.css"
      ]
    }
  ]
}