Examine source code of Change Tab Title

{
  "manifest_version": 2,
  "name": "Change Tab Title",
  "version": "1.0",
  "description": "Change the title of a tab.",
  "permissions": [
    "activeTab"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{2845d3e7-0f3f-4c87-8892-54c5a3cf4dde}"
    }
  }
}