Examine source code of Opera Cashback

{
  "name": "__MSG_extensionLongName__",
  "description": "__MSG_extensionDescription__",
  "version": "2.0.54",
  "author": "Opera",
  "default_locale": "en",
  "developer": {
    "name": "Opera",
    "url": "https://cashback.opera.com"
  },
  "homepage_url": "https://cashback.opera.com",
  "manifest_version": 2,
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "permissions": [
    "storage",
    "webRequest",
    "tabs",
    "activeTab",
    "<all_urls>"
  ],
  "page_action": {
    "default_popup": "index.html",
    "default_title": "__MSG_extensionName__",
    "default_icon": "icons/128/Icon_Light_Neutral.png"
  },
  "icons": {
    "32": "icons/32/Icon_Light_Neutral.png",
    "128": "icons/128/Icon_Light_Neutral.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{65d3f0e5-233f-4bb6-a8b4-cf2bbf96b95d}"
    }
  }
}