Examine source code of Peacock Title Bar

{
  "manifest_version": 2,
  "name": "Peacock",
  "version": "1.0",
  "description": "Customize the color of your Firefox window title bars.",
  "homepage_url": "https://github.com/benmccown/firefox-peacock",
  "permissions": [
    "tabs",
    "theme",
    "storage"
  ],
  "icons": {
    "58": "./assets/icon/bird-58.png"
  },
  "background": {
    "scripts": [
      "./background.js"
    ]
  },
  "browser_action": {
    "browser_style": true,
    "default_popup": "./assets/html/browser-action.html",
    "default_icon": {
      "58": "./assets/icon/bird-58.png"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{24cd1fcb-efc9-42f9-a7dd-87cc6fcb107d}"
    }
  }
}