Examine source code of Ambient Tab Sound

{
  "manifest_version": 2,
  "name": "Ambient Tab Sound",
  "version": "1.0",
  "description": "Plays ambient background sounds depending on the domain of the tab.",
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_icon": "icon.png",
    "default_title": "Ambient Tab Sound"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{fdf612d5-b5ec-4088-90dd-bad124fe7b4e}"
    }
  }
}