The GamePad API is an API that allows users to interact directly with web applications using a gamepad plugged into their PC. This could be used for numerous applications such as online gaming, virtual reality, or accessibility. In January 2018, a Chromium bug report was created to add support for the Nintendo Switch Pro controller. A new commit was created that adds better support to a variety of Nintendo Switch controllers that are connected to a computer via USB or Bluetooth. This commit is currently waiting for review before it can make it to the main Chromium development branch.
Source: https://www.bleepingcomputer.com/news/google/google-chrome-adding-support-for-nintendo-switch-gamepads/