Examine source code of QR codes

{
  "name": "QR codes",
  "description": "Generate QR code for current tab",
  "manifest_version": 2,
  "version": "0.1",
  "permissions": [
    "find",
    "tabs"
  ],
  "icons": {
    "48": "icons/icon-48.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "page_action": {
    "default_icon": "icons/page_action-32.svg",
    "default_title": "Generate QR code for this page",
    "show_matches": [
      "<all_urls>"
    ],
    "default_popup": "popup/popup.html"
  },
  "web_accessible_resources": [
    "assets/*.png",
    "assets/*.gif"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{4b89a0f7-dc43-4b77-ab9b-3a4e8c835fb5}"
    }
  }
}