1889639 - Disable WebGPU on 32-bit targets

Status: NEW

(Core :: Graphics: WebGPU, task, P1)

Description

[Erich Gubler [:ErichDonGubler] (he/him)]

Currently, 32-bit targets may expose some WebGPU functionality. We need to change this to return a null adapter for 32-bit targets' calls to GPUNavigator.requestAdapter—thereby cutting off all other WebGPU API surface—because we explicitly don't support them.

In CI, we need to enable some test that ensures that (1) we do get navigator.gpu and (2) await navigator.gpu.requestAdapter() always resolves to null.

N.B. that returning a null adapter is more appropriate than not setting navigator.gpu, because navigator.gpu indicates that the agent supports WebGPU, while a null adapter means the environment doesn't seem to.