[WebGPU] GPUCommandEncoder.clearBuffer does not appear to work.

Apply the following patch to instanced-textured-cube.js:

diff --git a/Websites/webkit.org/demos/webgpu/scripts/instanced-textured-cube.js b/Websites/webkit.org/demos/webgpu/scripts/instanced-textured-cube.js
index 4eb3defa62d4..3820afb3770e 100644
--- a/Websites/webkit.org/demos/webgpu/scripts/instanced-textured-cube.js
+++ b/Websites/webkit.org/demos/webgpu/scripts/instanced-textured-cube.js
@@ -334,6 +334,7 @@ async function helloCube() {
         
         /* GPUCommandEncoder */
         const commandEncoder = device.createCommandEncoder();
+        commandEncoder.clearBuffer(translationBuffer);
         /* GPURenderPassEncoder */
         const renderPassEncoder = commandEncoder.beginRenderPass(renderPassDescriptor);


it still seems to work as usual with an occasional flash. Which means the clear isn't happening in general or consistently.