Examine source code of statcounter blocking

{
  "manifest_version": 2,
  "name": "Statcounter blocking",
  "version": "2.2",
  "description": "Prevent your page views from showing up in your statcounter stats",
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png"
  },
  "permissions": [
    "http://*/*",
    "https://*/*",
    "webRequest",
    "webRequestBlocking",
    "tabs",
    "storage"
  ],
  "browser_action": {
    "default_icon": "icon16.png",
    "default_title": "Statcounter Blocker",
    "default_popup": "options.html"
  },
  "background": {
    "scripts": [
      "background.js",
      "block3.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{483ef46f-de49-491d-b6ad-a7ae2244609d}",
      "strict_min_version": "42.0"
    }
  }
}