Examine source code of Broadcast icon

{
  "manifest_version": 2,
  "name": "Broadcast icon",
  "version": "1.0",
  "description": "The broadcast symbol is commonly used to represent the transmission of a wireless signal from a source into the surrounding environment, such as: radio waves, television, Wi-Fi, Bluetooth, or network signals.",
  "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": "{8a8d0280-fd86-47eb-b292-c8c99d6e9b00}"
    }
  }
}