Webstorm localhost for Chrome lagging heavily

Hello, sorry if this is in the wrong section or anything; first time Webstorm user.

I've been using Webstorm for about 1.5 months with zero problems, working on various Three.js projects. To test my progress, I've been opening the html files in Chrome via Webstorm.

However, a few hours ago, seemingly at random, this has started to cause my threejs application to lag heavily. This seems to be a problem with Webstorm opening Chrome specifically, because:

- I can open the HTML files with Chrome from my file explorer: no lag
- I can upload the files and access them in Chrome: no lag
- This problem has affected earlier versions of the app that never had any problems, and even completely different apps

I've tried restarting my computer, reinstalling Webstorm, reinstalling the Chrome extension, but the problem persists.

Does anyone have any idea?

EDIT:

Uninstalling and reinstalling Google Chrome seemed to do the trick, but I've managed to reproduce the problem.

There seems to be a single command that causes my entire webstorm chrome testing environment to start lagging across all projects:

var infoDiv = $("#info");

infoDiv.animate({
 up: '21%'
});

With JQuery being loaded in through this URL:

https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js

The idea of this piece of code is to animate a div onscreen (hidden offscreen with overflow hidden).

Did I just do something really stupid?