Examine source code of Save PDF

{
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "description": "Save current page as PDF",
  "developer": {
    "name": "Didier Lafleur"
  },
  "icons": {
    "64": "icon.png"
  },
  "manifest_version": 2,
  "name": "Save PDF",
  "version": "0.2resigned1",
  "browser_action": {
    "default_title": "Save page as PDF",
    "default_icon": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{077f4ca9-a296-4624-9524-4e9b3835f512}"
    }
  }
}