Examine source code of WebDiff

{
  "manifest_version": 2,
  "name": "WebDiff",
  "version": "1.1.4",
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "options_ui": {
    "open_in_tab": true,
    "page": "options.html"
  },
  "background": {
    "scripts": [
      "js/background.js"
    ]
  },
  "permissions": [
    "<all_urls>"
  ],
  "web_accessible_resources": [
    "<all_urls>",
    "icons/*"
  ],
  "content_security_policy": "script-src 'self' 'unsafe-eval'; object-src 'self'",
  "browser_action": {
    "default_title": "WebDiff",
    "default_icon": "icons/icon.png",
    "default_popup": "popup.html"
  }
}