Examine source code of herowars notifer

{
  "manifest_version": 2,
  "name": "herowars notifer",
  "version": "1.0.4.2resigned1",
  "author": "hero-wars.info",
  "description": "hwc notifer",
  "icons": {
    "48": "assets/icons/icon-48-a.png"
  },
  "applications": {
    "gecko": {
      "id": "support@ilamer.ru",
      "strict_min_version": "58.0"
    }
  },
  "browser_action": {
    "default_icon": "assets/icons/icon-48-i.png",
    "default_title": "Hero Wars Notifier",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://ilamer.ru/hw/ref/*",
        "*://i-heroes-vk.nextersglobal.com/iframe_new/vkontakte/heroes/*"
      ],
      "all_frames": true,
      "js": [
        "assets/js/inject.js"
      ]
    }
  ],
  "permissions": [
    "storage",
    "notifications"
  ],
  "background": {
    "scripts": [
      "vendor/js/legacy.js",
      "vendor/js/Pushd4ClientWar.js",
      "background.js"
    ]
  }
}