Examine source code of Shipping Container Icon

{
  "manifest_version": 2,
  "name": "Shipping Container Icon",
  "version": "1.0",
  "description": "The shipping container symbol typically represents a large cargo container used in sea, road or rail transport.",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html",
    "default_title": "Click me!"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{60791fe6-5214-4f50-b79d-189e139e607c}"
    }
  }
}