Examine source code of Display Webpage Title

{
  "manifest_version": 2,
  "name": "Webpage Title Display",
  "version": "1.0",
  "description": "Displays the title of the current webpage.",
  "icons": {
    "48": "icons/icon.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": {
      "48": "icons/icon.png"
    },
    "default_popup": "popup.html"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{a145a70e-7db3-45c6-a3d6-735e7ffa7143}"
    }
  }
}