CoreAnimation is not a private API. Everything directly mentioned in that post is public API. Firefox may use private API but it’s not mentioned in the post.
Contents property itself is not a private API. Quality of docs I can't speak to, but it's a different issue than private API (which is stuff that's not in the public SDK).
The second link has private APIs, and the header file to access those private APIs still exists in WebKit for MacOS. I mentioned both undocumented and private. The first link just shows that if you are Apple, you can correctly call APIs that provide a performance increase on MacOS.
Because of that, my recommendation is to just stop using MacOS if you care about browser performance.
> the header file to access those private APIs still exists in WebKit for MacOS
The most these headers can do is maybe help with rendering performance, of which I'm not completely certain that there are still APIs that Safari uses that other browsers don't. I cannot see how benchmark scores from e.g. JavaScriptCore would be affected.
> Because of that, my recommendation is to just stop using MacOS if you care about browser performance.
And private APIs that still aren't available, as I noted in the second section you responded to.
> The most these headers can do is maybe help with rendering performance
Exactly. Everything I referenced was about rendering performance. I never claimed otherwise, so don't derail the argument by strawmanning JavaScriptCore vs. V8 on MacOS.
> Your point doesn't logically follow.
If you want the most speed, you want to use a platform that gives everyone access to APIs that enable it. QED.
