Examine source code of Webpage Description

{
  "manifest_version": 2,
  "name": "Webpage Description",
  "version": "1.0",
  "description": "Displays the description of the webpage.",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_icon": {
      "48": "icon.png"
    },
    "default_popup": "popup.html"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{d6d72bdc-1221-4ecf-bffc-31b2b303cff9}"
    }
  }
}