Examine source code of Second Search

{
  "manifest_version": 2,
  "name": "__MSG_extensionName__",
  "version": "2.3.9",
  "author": "YUKI \"Piro\" Hiroshi",
  "description": "__MSG_extensionDescription__",
  "permissions": [
    "https://www.google.com/s2/favicons?*",
    "https://*.gstatic.com/favicon*",
    "activeTab",
    "bookmarks",
    "search",
    "storage",
    "theme"
  ],
  "optional_permissions": [
    "<all_urls>"
  ],
  "icons": {
    "16": "/resources/16x16.svg#default-bright",
    "32": "/resources/32x32.svg#default-bright"
  },
  "background": {
    "scripts": [
      "/common/constants.js",
      "/extlib/Configs.js",
      "/common/common.js",
      "/common/permissions.js",
      "/background/background.js"
    ]
  },
  "browser_action": {
    "default_title": "__MSG_panelTitle__",
    "default_icon": {
      "16": "/resources/16x16.svg#toolbar-bright",
      "32": "/resources/32x32.svg#toolbar-bright"
    },
    "browser_style": false,
    "default_popup": "panel/panel.html",
    "theme_icons": [
      {
        "light": "/resources/16x16.svg#toolbar-bright",
        "dark": "/resources/16x16.svg#toolbar-dark",
        "size": 16
      },
      {
        "light": "/resources/32x32.svg#toolbar-bright",
        "dark": "/resources/32x32.svg#toolbar-dark",
        "size": 32
      }
    ]
  },
  "commands": {
    "_execute_browser_action": {
      "description": "__MSG_commandDescription__",
      "suggested_key": {
        "default": "Ctrl+Shift+L"
      }
    }
  },
  "options_ui": {
    "page": "/options/options.html",
    "browser_style": false
  },
  "default_locale": "en",
  "applications": {
    "gecko": {
      "id": "{0AE5CAA4-8BAB-11DB-AF59-ED4B56D89593}",
      "strict_min_version": "63.0"
    }
  }
}