EDIT: If you want proof that this ACTUALLY DOES change something. Before following this tutorial, Create a room in Haxball, or Join one, start the game, hold the 'ESC' button, see how slow/laggy the screen is while updating itself. You will also notice that the game takes a bit longer to respond to your key presses.
Now follow the tutorial. After you're back to using the normal Adobe Flash Player, do the same thing and see how fast the screen updates itself.
After looking at this:
What happened with new chrome?
Chrome has Flash player embedded into it (or something along those lines I'm not a tech geek) and thusly will update with Flash player. The new Flash player has something called Flash block or something that prevents video autoplay and thusly will make Haxball very choppy.
(This is what I think I learned from Dgby)
I RECOMMEND MAXTHON OVER THIS.
I decided to check more into it and found out a way to disable this "Embedded Flash Player" in Chrome.
You'll also need to follow this guide if you want your flag change hack to work after this Chrome update.
Open a new tab in Chrome.
In the address bar type chrome:plugins and hit enter. (if it doesn't work type chrome://plugins)
Hit the details button
Search for this (picture below will explain further):Make sure you disable the one that says about PepperFlash, not the other one.
At the end it should look like this: