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/window.rs

@@ -136,6 +136,7 @@ use style::str::HTML_SPACE_CHARACTERS;
 use style::stylesheets::CssRuleType;
 use style_traits::{CSSPixel, DevicePixel, ParsingMode};
 use url::Position;
+use webgpu::WebGPU;
 use webrender_api::units::{DeviceIntPoint, DeviceIntSize, LayoutPixel};
 use webrender_api::{DocumentId, ExternalScrollId, RenderApiSender};
 use webvr_traits::WebVRMsg;
@@ -267,6 +268,10 @@ pub struct Window {
     #[ignore_malloc_size_of = "channels are hard"]
     webgl_chan: Option<WebGLChan>,
 
+    #[ignore_malloc_size_of = "channels are hard"]
+    /// A handle for communicating messages to the WebGPU threads.
+    webgpu: Option<WebGPU>,
+
     /// A handle for communicating messages to the webvr thread, if available.
     #[ignore_malloc_size_of = "channels are hard"]
     webvr_chan: Option<IpcSender<WebVRMsg>>,
@@ -462,6 +467,10 @@ impl Window {
             .map(|chan| WebGLCommandSender::new(chan.clone(), self.get_event_loop_waker()))
     }
 
+    pub fn webgpu_channel(&self) -> Option<WebGPU> {
+        self.webgpu.clone()
+    }
+
     pub fn webvr_thread(&self) -> Option<IpcSender<WebVRMsg>> {
         self.webvr_chan.clone()
     }
@@ -2206,6 +2215,7 @@ impl Window {
         navigation_start: u64,
         navigation_start_precise: u64,
         webgl_chan: Option<WebGLChan>,
+        webgpu: Option<WebGPU>,
         webvr_chan: Option<IpcSender<WebVRMsg>>,
         webxr_registry: webxr_api::Registry,
         microtask_queue: Rc<MicrotaskQueue>,
@@ -2285,6 +2295,7 @@ impl Window {
             media_query_lists: DOMTracker::new(),
             test_runner: Default::default(),
             webgl_chan,
+            webgpu,
             webvr_chan,
             webxr_registry,
             permission_state_invocation_results: Default::default(),