Examine source code of SmartTab

{
  "manifest_version": 2,
  "name": "SmartTab",
  "version": "1.0.0",
  "description": "A beautiful, fast, and minimalist new tab page with search, notes, and quick access to your favorite sites.",
  "permissions": [
    "storage",
    "activeTab",
    "topSites",
    "history"
  ],
  "optional_permissions": [
    "tabs"
  ],
  "chrome_url_overrides": {
    "newtab": "newtab.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "content_security_policy": "script-src 'self'; object-src 'self'; base-uri 'self'; form-action 'self';",
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "SmartTab Settings",
    "default_icon": {
      "16": "icons/icon-16.png",
      "48": "icons/icon-48.png",
      "128": "icons/icon-128.png"
    }
  },
  "icons": {
    "16": "icons/icon-16.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{e76a4b3f-8031-4c8c-a3a3-8e315e9336d8}"
    }
  }
}