Chrome Version       : 73.0.3671.0
OS Version: OS X 10.14.2
URLs (if applicable) :
Other browsers tested:
  Add OK or FAIL after other browsers where you have tested this issue:
     Safari:
    Firefox:
    IE/Edge:

What steps will reproduce the problem?
1.
2.
3.

What is the expected result?


What happens instead of that?


Please provide any additional information below. Attach a screenshot if
possible.

UserAgentString: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3671.0 Safari/537.36



 

See e.g. https://codepen.io/miguelao/full/ZjJNNw on a current 73 Canary,

var ctx = canvas.getContext("2d", {lowLatency: true, alpha: false});

makes the canvas unusable because when drawing on it with the mouse
(click and drag) nothing is painted until we e.g. switch tabs or apps.

Disable lowLatency for Mac.