Examine source code of Dam icon

{
  "manifest_version": 2,
  "name": "Dam icon",
  "version": "1.0",
  "description": "A dam symbol is a symbol used to represent a hydroelectric dam, dam, or reservoir built by humans.",
  "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": "{d547cb0c-d429-4e7f-b7c2-30a73be621ce}"
    }
  }
}