Old hardware or misconfigured one may lead to tearing effect during video playbacks.
You may test your playback quality just watching this video on youtube
If you are running catalyst ATI drivers for ubuntu , you shall enable tearing free option in the driver config window. That’s a safe option if you are not a gamer.
If it doesn’t help and you still get tearing in chrome/chromium most probably chrome is not using any hardware acceleration.
You can check that from chrome://gpu/. In my case, since I run legacy ATI driver the hardware acceleration is switched off by default in chrome.
From chrome://flags I managed to disable the GPU blacklist (first option) in order to get tearing free playbacks!