Examine source code of DevTools Prototyper

{
  "manifest_version": 2,
  "name": "DevTools Prototyper",
  "version": "5.0a1",
  "description": "JSFiddle style prototyping.",
  "author": "Tim Nguyen",
  "devtools_page": "devtools_page.html",
  "permissions": [
    "<all_urls>",
    "tabs",
    "storage",
    "unlimitedStorage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  }
}