Examine source code of Clock Tab

{
  "name": "ClockTab",
  "description": "A new tab that displays time.",
  "version": "1.0.0",
  "permissions": [
    "tabs"
  ],
  "manifest_version": 2,
  "author": "Gautham Krishna",
  "icons": {
    "16": "/favicon-16x16.png",
    "32": "/favicon-32x32.png",
    "192": "/favicon-192x192.png",
    "512": "/favicon-512x512.png"
  },
  "chrome_url_overrides": {
    "newtab": "./index.html"
  },
  "browser_action": {
    "default_icon": {
      "16": "/favicon-16x16.png",
      "32": "/favicon-32x32.png",
      "192": "/favicon-192x192.png",
      "512": "/favicon-512x512.png"
    }
  }
}