Examine source code of Tab Mix Plus

{
  "manifest_version": 2,
  "name": "Tab Mix Plus (Lite)",
  "version": "1.0.0",
  "description": "Lightweight Tab Mix Plus features: tab duplication, protect tab from closing, reopen last closed tab, session save/restore. No external resources, stores settings locally.",
  "permissions": [
    "tabs",
    "storage",
    "sessions",
    "contextMenus",
    "notifications",
    "activeTab"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_title": "Tab Mix Plus",
    "default_popup": "popup.html"
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "icons": {},
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "browser_specific_settings": {
    "gecko": {
      "id": "{2224219b-1284-4702-b097-c1b85f23d2b1}"
    }
  }
}