Examine source code of YoutubeTab

{
  "manifest_version": 2,
  "name": "Youtube",
  "version": "1.0",
  "description": "Access youtube in a new tab",
  "icons": {
    "48": "icons/48.png",
    "96": "icons/96.png",
    "144": "icons/144.png",
    "240": "icons/240.png",
    "480": "icons/480.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": "icons/64.png",
    "default_title": "Youtube"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{49b48486-d391-4df1-b9e1-3e63597c22d5}"
    }
  }
}