Examine source code of Screen Sharing Discord

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "manifest_version": 2,
  "name": "Discord Screen Sharing",
  "description": "Share the screen from your computer on Discord.",
  "version": "0.0.4",
  "minimum_chrome_version": "34",
  "icons": {
    "16": "icons/16.png",
    "26": "icons/26.png",
    "48": "icons/48.png",
    "128": "icons/128.png"
  },
  "background": {
    "persistent": true,
    "scripts": [
      "src/background.js"
    ]
  },
  "permissions": [
    "desktopCapture"
  ],
  "externally_connectable": {
    "matches": [
      "*://discordapp.com/*",
      "*://*.discordapp.com/*",
      "*://*.discord.co/*",
      "*://localhost/*"
    ]
  }
}