You can probably find your browser's driver blacklist at: https://www.khronos.org/webgl/wiki/BlacklistsAndWhitelists
Other than that, it's mostly a function (from what I can tell) of your GPU's capabilities and your drivers. Generally, a better GPU (esp. when it comes to rendering shaders) should mean better Unity WebGL performance- but don't quote me on this.
If this game works fine, your browser/device shouldn't have any serious issues with WebGL in and of itself: http://flightarcade.com
Edited 1/24/2018 15:49:06