WebGPU requires timestamps in nanoseconds

[Draradech]

WebGPU requires timestamps in nanoseconds (https://gpuweb.github.io/gpuweb/#timestamp)
wgpu requires multiplication with get_timestamp_period (https://docs.rs/wgpu/latest/wgpu/enum.QueryType.html#variant.Timestamp)

This results in Firefox (135.0a1 (2024-12-11)) reporting wrong values on devices which don't use nanosecond resolution for their timestamps (like Intel Iris Xe)
Chart lists times (in ms) as wallclock / ts-query:

Test code (web and wgpu-py) is available here: https://glitch.com/edit/#!/rowan-pinnate-yacht

For reference: #3741

[Wumpf]

Firefox not providing the correct values is somewhat orthogonal arguably. Yes, as it stands Firefox has to implement a compute pass to convert the timestamp on-gpu when implementing WebGPU using wgpu since that's how wgpu is specified today.
However, I think we want at least be able to allow to avoid this additional overhead of gpu sided timestamp conversion. But likely that should be opt-in rather opt-out, otherwise it's confusing for anyone who is reasonably expecting wgpu to behave like the WebGPU api in that regard! 🤔

[cwfitzgerald]

Yeah native should be off, using the timestamp period, and Firefox will turn it on in core.

Still need to implement it in wgpu though.