Examine source code of Tracking protection icon

{
  "manifest_version": 2,
  "name": "__MSG_extensionName__",
  "description": "__MSG_extensionDescription__",
  "default_locale": "en",
  "version": "0.0.2resigned1",
  "author": "Nukeador",
  "homepage_url": "https://github.com/nukeador/tracking-protection-icon",
  "icons": {
    "48": "images/icon-48.png",
    "96": "images/icon-96.png"
  },
  "permissions": [
    "tabs",
    "privacy"
  ],
  "page_action": {
    "default_icon": "images/icon-off.svg"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{6fd5c1d9-790c-4a6f-9c77-17dbb77bb935}"
    }
  }
}