Update WebGPU bindings (#14951)

* Update WebGPU bindings

Fix changed items in header and implementation.
- Change WGPUSurface to represent a context instead of just a canvas to
  handle the removal of GPUSwapChain.
- Change some magic numbers to named constants.

* Rebaseline reference_struct_info.json

* Minify some unnecessarily verbose checks

* Add missing asserts in buffer mapping functions

* Implement wgpuSurfaceGetPreferredFormat

* Implement adapter/device entry points

- WGPUAdapter objects
- wgpuInstanceRequestAdapter
- wgpuAdapterRequestDevice
- wgpuAdapterGetProperties
- wgpuDeviceDestroy

* Implement error handling functions

- wgpuDevicePushErrorScope/wgpuDevicePopErrorScope (untested)
- wgpuDeviceSetDeviceLostCallback (semi-tested)

* Add WebGPU browser test

* Add externs for all WebGPU interfaces/namespaces

Author: kainino0x

src/closure-externs/closure-externs.js

@@ -296,8 +296,42 @@ var sampleRate;
 /*
  * WebGPU globals
  */
-var GPUValidationError;
+var GPUBufferUsage;
+var GPUColorWrite;
+var GPUMapMode;
+var GPUShaderStage;
+var GPUTextureUsage;
+var GPU;
+var GPUAdapter;
+var GPUBindGroup;
+var GPUBindGroupLayout;
+var GPUBuffer;
+var GPUCanvasContext;
+var GPUCommandBuffer;
+var GPUCommandEncoder;
+var GPUCompilationInfo;
+var GPUCompilationMessage;
+var GPUComputePassEncoder;
+var GPUComputePipeline;
+var GPUDevice;
+var GPUDeviceLostInfo;
+var GPUExternalTexture;
 var GPUOutOfMemoryError;
+var GPUPipelineLayout;
+var GPUQuerySet;
+var GPUQueue;
+var GPURenderBundle;
+var GPURenderBundleEncoder;
+var GPURenderPassEncoder;
+var GPURenderPipeline;
+var GPUSampler;
+var GPUShaderModule;
+var GPUSupportedFeatures;
+var GPUSupportedLimits;
+var GPUTexture;
+var GPUTextureView;
+var GPUUncapturedErrorEvent;
+var GPUValidationError;
 
 /*
  * Avoid closure minifying anything to "id". See #13965