rem unit does not work on canvas context leading to cross-browser issues. Here is a codepen: https://codepen.io/ashishsantikari/pen/zYGGbMa Compare the output on gecko and webkit. Tested on build r256302. Hardware: MacBook Pro (13-inch, 2019, Four Thunderbolt 3 ports) OS: macOS Catalina 10.15.3 (19D76)
<rdar://problem/59359893>