Examine source code of Save In Booru Edition

{
  "manifest_version": 2,
  "name": "Save In Booru Edition",
  "description": "__MSG_extensionDescription__",
  "version": "3.7.4",
  "default_locale": "en",
  "browser_specific_settings": {
    "gecko": {
      "id": "save-in-booru@borez",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "developer": {
    "name": "Ng Guoyou",
    "url": "https://github.com/gyng/save-in"
  },
  "homepage_url": "https://github.com/gyng/save-in",
  "background": {
    "scripts": [
      "src/vendor/browser-polyfill.js",
      "src/vendor/content-disposition.js",
      "src/chrome-detector.js",
      "src/constants.js",
      "src/history.js",
      "src/notification.js",
      "src/path.js",
      "src/download.js",
      "src/router.js",
      "src/shortcut.js",
      "src/messaging.js",
      "src/headers.js",
      "src/variable.js",
      "src/menu.js",
      "src/option.js",
      "src/index.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "src/content/content.js"
      ]
    }
  ],
  "permissions": [
    "<all_urls>",
    "activeTab",
    "tabs",
    "contextMenus",
    "downloads",
    "notifications",
    "storage",
    "webRequest",
    "webRequestBlocking"
  ],
  "options_ui": {
    "browser_style": true,
    "chrome_style": true,
    "page": "src/options/options.html"
  },
  "icons": {
    "48": "icons/ic_archive_black_48px.png",
    "96": "icons/ic_archive_black_96px.png",
    "128": "icons/ic_archive_black_128px.png"
  }
}