Examine source code of PDF for iFrames

{
  "browser_action": {
    "browser_style": true,
    "default_title": "PDF Opener",
    "default_popup": "dummy.html",
    "default_icon": {
      "19": "icons/default19.png",
      "38": "icons/default38.png"
    }
  },
  "description": "Opens iframe PDFs in a new tab which is downloadable",
  "icons": {
    "48": "icons/cookie.png",
    "96": "icons/cookie@2x.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "manifest_version": 2,
  "name": "PDF for iFrames",
  "version": "1.0",
  "permissions": [
    "<all_urls>",
    "tabs",
    "webRequest",
    "webRequestBlocking"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{745814a7-a196-4b07-b231-7cffc20ad630}"
    }
  }
}