Examine source code of Music Player

{
  "manifest_version": 2,
  "name": "Music Player",
  "version": "1.1",
  "permissions": [
    "storage",
    "tabs",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "commands": {
    "previous-song": {
      "suggested_key": {
        "default": "F7"
      },
      "description": "Previous pinned tab"
    },
    "next-song": {
      "suggested_key": {
        "default": "F8"
      },
      "description": "Next pinned tab"
    }
  },
  "icons": {
    "48": "icons/icon48-light.png",
    "128": "icons/icon128-light.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "music_player@extension.org",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}