I recently updated Google Chrome to the 61.0.3163.79 version and it was suddenly very slow with canvas. This issue only appears on Linux.
For exemple, http://vincentgarreau.com/particles.js/ was 60 FPS before the Chrome update, and now it run at 2 FPS.
What's wrong with the new Google Chrome update ?
P.S: Chromium 61.0.3163.79 works fine on my computer.
I found workaround. After upgrade Chrome to 61 version I faced same experience with you.
Try adjust following chrome flag to Disabled.
I expect Default flag have different means with before 61 version. Below the result is in my case on attached url from you.
Default - 5 fps
Disabled - 35 fps
I wish this help you.