Add toneMapping and getConfiguration()

[chrisdavidmills]

Summary

This PR adds two new WebGPU features added recently in Chrome:

• The GPUCanvasContext.getConfiguration() method, added in Chrome 131 (see relevant ChromeStatus entry).
• The GPUCanvasContext configuration toneMapping option, added in Chrome 129 (see relevant ChromeStatus entry).

Test results and supporting details

Features testing in Chrome 131 with the following snippet:

const canvas = document.querySelector("canvas");
const context = canvas.getContext("webgpu");

async function init() {
  if (!navigator.gpu) {
    throw Error("WebGPU not supported.");
  }

  const adapter = await navigator.gpu.requestAdapter();
  if (!adapter) {
    throw Error("Couldn't request WebGPU adapter.");
  }

  const device = await adapter.requestDevice();

  context.configure({
    device: device,
    format: navigator.gpu.getPreferredCanvasFormat(),
    alphaMode: "premultiplied",
    toneMapping: {
      mode: "extended"
    }
  });

  console.log(context.getConfiguration());
}

init();

Related issues

[Elchi3]

LGTM, thanks Chris 👍