[macOS] Switch ANGLE backend to ANGLE over OpenGL, switch default compatibility renderer back to native.

[bruvzg]

I think it's pretty clear that using ANGLE over Metal on macOS was a total failure. Unlike ANGLE over DX11 on Windows which seems to be doing a good job for supporting older hardware, it's causing a lot more issues than fixing.

Superseded #84563
Fixes #85619
Fixes #84591

[akien-mga]

Is there much value left in using ANGLE over OpenGL as opposed to just native OpenGL? The main rationale for using ANGLE on macOS was the fear that bitrotting OpenGL drivers would have too many issues, but if we're still using them via ANGLE there might not be much benefit in having ANGLE at all?

On the other hand if there we still want to have ANGLE over Metal as an opt-in for devices with proper Metal support, we could still considering #84563. But it sounds like ANGLE over Metal has core issues even on latest macOS?

[bruvzg]

Is there much value left in using ANGLE over OpenGL as opposed to just native OpenGL?

The only issues with ANGLE over OpenGL is slow shader compilation (first start will take minute or two, some WebGL issue we have on macOS), and it's not fixing GPU particles issues. It might be fixing some issues, but I'm not sure. So we probably should not have it built-in, but keeping support for dynamically linked versions cost noting (most of the code is shared with Windows, and EGL on Linux), so I do not see many reasons to completely remove macOS specific part of it.

The main rationale for using ANGLE on macOS was the fear that bitrotting OpenGL drivers would have too many issues, but if we're still using them via ANGLE there might not be much benefit in having ANGLE at all?

Unlikely it will get less functional, and when OpenGL is removed from macOS, I would expect Google to fix all issues in the ANGLE over Metal (unless WebGPU will supersede it by the time) for the use in Chromium.

On the other hand if there we still want to have ANGLE over Metal as an opt-in for devices with proper Metal support

With this amount of issues I would not consider it even as an optional feature.

[akien-mga]

Thanks!

[akien-mga]

Cherry-picked for 4.2.1.