Examine source code of Send to MyInfo (legacy)

{
  "name": "__MSG_extensionName__",
  "description": "__MSG_extensionDescription__",
  "version": "2.3.0",
  "default_locale": "en",
  "background": {
    "page": "background.html"
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "extension_installed.js"
      ],
      "run_at": "document_end"
    }
  ],
  "icons": {
    "16": "images/icon-16x16.png",
    "48": "images/icon-48x48.png",
    "128": "images/icon-128x128.png"
  },
  "permissions": [
    "activeTab",
    "contextMenus",
    "nativeMessaging"
  ],
  "browser_action": {
    "default_title": "Send to MyInfo",
    "default_icon": "images/icon-16x16.png",
    "default_popup": "popup.html"
  },
  "applications": {
    "gecko": {
      "id": "{9208b9ae-7f13-4aed-98b0-d7dac127f253}"
    }
  },
  "manifest_version": 2
}