Examine source code of SAML Message Decoder

{
  "manifest_version": 2,
  "name": "SAML Message Decoder",
  "description": "Collects and displays SAML messages",
  "version": "2.1.2resigned1",
  "browser_action": {
    "default_popup": "index.html",
    "default_icon": {
      "16": "static/icon_16.png",
      "48": "static/icon_48.png",
      "128": "static/icon_128.png"
    }
  },
  "icons": {
    "16": "static/icon_16.png",
    "48": "static/icon_48.png",
    "128": "static/icon_128.png"
  },
  "permissions": [
    "<all_urls>",
    "webRequest",
    "contextMenus",
    "storage",
    "downloads"
  ],
  "background": {
    "scripts": [
      "listener.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{6797dc39-b80a-4d51-a2ab-f58debd210d8}"
    }
  }
}