Examine source code of ChrHome

{
  "name": "ChrHome",
  "short_name": "ChrHome",
  "version": "1.1.0",
  "manifest_version": 2,
  "description": "A clock frame for your TV",
  "icons": {
    "16": "16px-Human-go-home.svg.png",
    "48": "128px-Human-go-home.svg.png",
    "128": "128px-Human-go-home.svg.png"
  },
  "browser_action": {
    "default_icon": "16px-Human-go-home.svg.png",
    "default_title": "Pic Clock Home"
  },
  "background": {
    "persistent": false,
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://clients3.google.com/cast/chromecast/home"
      ],
      "js": [
        "contentscript.js"
      ]
    }
  ],
  "permissions": [],
  "content_security_policy": "script-src 'self' ; object-src 'self'"
}