Auto merge of #24708 - szeged:webgpu-base, r=gterzian,kvark

Initial implementation of WebGPU API

<!-- Please describe your changes on the following line: -->
- Added the WebIDL bindings for GPU and GPUadapter interfaces.
- Created a background thread for WebGPU api calls.
- Established the async communication between the background thread and the WebGPU interfaces.
- Implemented the `requesAdapter` function of `navigator.gpu`

`./mach test-tidy` reports an error due to the different `arrayvec` version used in `servo` and `webgpu`, so added it to the ignore list in `servo-tidy.toml`

---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `___` with appropriate data: -->
- [x] `./mach build -d` does not report any errors
- [ ] `./mach test-tidy` does not report any errors
- [ ] These changes addresses a part of #https://github.com/servo/servo/issues/24706

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cc @jdm, cc @kvark

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components/script/dom/webidls/GPU.webidl

@@ -0,0 +1,21 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+// https://gpuweb.github.io/gpuweb/#gpu-interface
+[Exposed=(Window, DedicatedWorker), Pref="dom.webgpu.enabled"]
+interface GPU {
+    // May reject with DOMException  // TODO: DOMException("OperationError")?
+    Promise<GPUAdapter> requestAdapter(optional GPURequestAdapterOptions options = {});
+};
+
+// https://gpuweb.github.io/gpuweb/#dictdef-gpurequestadapteroptions
+dictionary GPURequestAdapterOptions {
+    GPUPowerPreference powerPreference;
+};
+
+// https://gpuweb.github.io/gpuweb/#enumdef-gpupowerpreference
+enum GPUPowerPreference {
+    "low-power",
+    "high-performance"
+};

components/script/dom/webidls/GPUAdapter.webidl

@@ -0,0 +1,14 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+// https://gpuweb.github.io/gpuweb/#gpuadapter
+[Exposed=(Window, DedicatedWorker), Pref="dom.webgpu.enabled"]
+interface GPUAdapter {
+    readonly attribute DOMString name;
+    readonly attribute object extensions;
+    //readonly attribute GPULimits limits; Don’t expose higher limits for now.
+
+    // May reject with DOMException  // TODO: DOMException("OperationError")?
+    // Promise<GPUDevice> requestDevice(optional GPUDeviceDescriptor descriptor = {});
+};

components/script/dom/webidls/Navigator.webidl

@@ -75,3 +75,8 @@ partial interface Navigator {
 partial interface Navigator {
     [Pref="dom.gamepad.enabled"] GamepadList getGamepads();
 };
+
+[Exposed=Window]
+partial interface Navigator {
+    [SameObject, Pref="dom.webgpu.enabled"] readonly attribute GPU gpu;
+};

components/script/dom/webidls/WorkerNavigator.webidl

@@ -15,3 +15,8 @@ WorkerNavigator includes NavigatorLanguage;
 partial interface WorkerNavigator {
   [Pref="dom.permissions.enabled"] readonly attribute Permissions permissions;
 };
+
+[Exposed=DedicatedWorker]
+partial interface WorkerNavigator {
+    [SameObject, Pref="dom.webgpu.enabled"] readonly attribute GPU gpu;
+};