Makes tabs and windows think they're visible even when they're not.
このスクリプトは単体で利用できません。右のようなメタデータを含むスクリプトから、ライブラリとして読み込まれます: // @require https://update.greasyfork.org/scripts/456228/1309113/Absolute%20Visibility.js
Based on https://addons.mozilla.org/en-US/firefox/addon/always-visible/ and turned into a library that can be used on other UserScripts to disable visible state changes in websites.
