Examine source code of CSS Sentry

{
  "manifest_version": 2,
  "name": "CSS Sentry",
  "description": "Browser extension for detecting and reducing CSS-based data exfiltration risk.",
  "version": "1.0.107",
  "icons": {
    "16": "icons/16.png",
    "32": "icons/32.png",
    "48": "icons/48.png",
    "128": "icons/128.png"
  },
  "permissions": [
    "storage",
    "declarativeNetRequest",
    "webNavigation",
    "webRequest",
    "webRequestBlocking",
    "<all_urls>"
  ],
  "options_ui": {
    "open_in_tab": false,
    "page": "options.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "css-sentry@dougg0k",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Default Popup Title",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "all_frames": true,
      "run_at": "document_start",
      "js": [
        "content-scripts/content.js"
      ]
    }
  ]
}