Web Inspector: Canvas: don't show an empty preview for WebGPU devices

[Devin Rousso]

`HTMLCanvasElement.prototype.toDataURL` hasn't been hooked up for `GPUCanvasContext` yet, so calling `Canvas.requestContent` with a `WebGPUDevice` won't give us any good results.  As such, the Web Inspector frontend should show something slightly more actionable, or at the very least something less obviously wrong.

[Devin Rousso]

Created attachment 380393 [details]
Patch

[Devin Rousso]

Created attachment 380394 [details]
[Image] After Patch is applied

[Matt Baker]

Comment on attachment 380393 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=380393&action=review

r=me

> Source/WebInspectorUI/UserInterface/Models/Canvas.js:127
> +        return true;

I know this was written with future contextTypes in mind, but I'd just replace it with:

return contextType !== Canvas.ContextType.WebGPU && contextType !== Canvas.ContextType.WebMetal;

[Devin Rousso]

Comment on attachment 380393 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=380393&action=review

>> Source/WebInspectorUI/UserInterface/Models/Canvas.js:127
>> +        return true;
> 
> I know this was written with future contextTypes in mind, but I'd just replace it with:
> 
> return contextType !== Canvas.ContextType.WebGPU && contextType !== Canvas.ContextType.WebMetal;

I personally prefer this, as it's more future-proof.

[WebKit Commit Bot]

Comment on attachment 380393 [details]
Patch

Clearing flags on attachment: 380393

Committed r250858: <https://trac.webkit.org/changeset/250858>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Radar WebKit Bug Importer]

<rdar://problem/56088775>