Examine source code of Items.com

{
  "background": {
    "persistent": false,
    "scripts": [
      "background.js"
    ]
  },
  "web_accessible_resources": [
    "css/*.css",
    "images/*"
  ],
  "content_scripts": [
    {
      "js": [
        "ext.js",
        "js/items_coupons.js",
        "js/activate_overlay.js"
      ],
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "run_at": "document_end",
      "all_frames": false
    }
  ],
  "browser_action": {
    "default_icon": {
      "16": "images/icons/16.png",
      "32": "images/icons/32.png",
      "48": "images/icons/48.png",
      "128": "images/icons/128.png"
    },
    "default_popup": "popup.html"
  },
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "description": "items.com Amazing Offers & Coupons. It's all about the discount & cashback!",
  "icons": {
    "16": "images/icons/16.png",
    "32": "images/icons/32.png",
    "48": "images/icons/48.png",
    "128": "images/icons/128.png"
  },
  "manifest_version": 2,
  "name": "Items",
  "permissions": [
    "tabs",
    "storage",
    "<all_urls>"
  ],
  "update_url": "https://clients2.google.com/service/update2/crx",
  "version": "2.10",
  "browser_specific_settings": {
    "gecko": {
      "id": "{4ec426d3-3721-46b0-b53a-1916ef9b5269}"
    }
  }
}