[WebGPU] Update texture creation validation

[Myles C. Maxfield]

[WebGPU] Update texture creation validation according to the discussion at https://github.com/gpuweb/gpuweb/pull/799/files

[Myles C. Maxfield]

Created attachment 400283 [details]
Patch

[Justin Fan]

Comment on attachment 400283 [details]
Patch

Looks good! I don't have the power to r+, though.

[Dean Jackson]

Comment on attachment 400283 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=400283&action=review

> Source/WebCore/platform/graphics/gpu/GPUDevice.cpp:153
>      if (descriptor.sampleCount != 1) {
> +        if (descriptor.sampleCount != 4) {
> +            m_errorScopes->generatePrefixedError("Texture sampleCount can only be 1 or 4.");
> +            return { };
> +        }

Could you move this to an early return?

if (descriptor.sampleCount != 1 && descriptor.sampleCount != 4) {
  error and return
} 

if (descriptor.sampleCount != 1) {
  // do the stuff for 4
}

[Myles C. Maxfield]

Committed r262407: <https://trac.webkit.org/changeset/262407>

[Radar WebKit Bug Importer]

<rdar://problem/63860411>