Initial implementation of GPUQueue

Added WebIDL bindings for `GPUQueue`.
Implemented the `submit` function of `GPUQueue` and `defaultQueue` function of `GPUDevice`.

components/script/dom/gpuqueue.rs

@@ -0,0 +1,73 @@
+/* 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/. */
+
+use crate::dom::bindings::cell::DomRefCell;
+use crate::dom::bindings::codegen::Bindings::GPUQueueBinding::{self, GPUQueueMethods};
+use crate::dom::bindings::reflector::{reflect_dom_object, Reflector};
+use crate::dom::bindings::root::DomRoot;
+use crate::dom::bindings::str::DOMString;
+use crate::dom::globalscope::GlobalScope;
+use crate::dom::gpubuffer::GPUBufferState;
+use crate::dom::gpucommandbuffer::GPUCommandBuffer;
+use dom_struct::dom_struct;
+use webgpu::{WebGPU, WebGPUQueue, WebGPURequest};
+
+#[dom_struct]
+pub struct GPUQueue {
+    reflector_: Reflector,
+    #[ignore_malloc_size_of = "defined in webgpu"]
+    channel: WebGPU,
+    label: DomRefCell<Option<DOMString>>,
+    queue: WebGPUQueue,
+}
+
+impl GPUQueue {
+    fn new_inherited(channel: WebGPU, queue: WebGPUQueue) -> GPUQueue {
+        GPUQueue {
+            channel,
+            reflector_: Reflector::new(),
+            label: DomRefCell::new(None),
+            queue,
+        }
+    }
+
+    pub fn new(global: &GlobalScope, channel: WebGPU, queue: WebGPUQueue) -> DomRoot<GPUQueue> {
+        reflect_dom_object(
+            Box::new(GPUQueue::new_inherited(channel, queue)),
+            global,
+            GPUQueueBinding::Wrap,
+        )
+    }
+}
+
+impl GPUQueueMethods for GPUQueue {
+    /// https://gpuweb.github.io/gpuweb/#dom-gpuobjectbase-label
+    fn GetLabel(&self) -> Option<DOMString> {
+        self.label.borrow().clone()
+    }
+
+    /// https://gpuweb.github.io/gpuweb/#dom-gpuobjectbase-label
+    fn SetLabel(&self, value: Option<DOMString>) {
+        *self.label.borrow_mut() = value;
+    }
+
+    /// https://gpuweb.github.io/gpuweb/#dom-gpuqueue-submit
+    fn Submit(&self, command_buffers: Vec<DomRoot<GPUCommandBuffer>>) {
+        let valid = command_buffers.iter().all(|cb| {
+            cb.buffers().iter().all(|b| match *b.state() {
+                GPUBufferState::Unmapped => true,
+                _ => false,
+            })
+        });
+        if !valid {
+            // TODO: Generate error to the ErrorScope
+            return;
+        }
+        let buffer_ids = command_buffers.iter().map(|cb| cb.id().0).collect();
+        self.channel
+            .0
+            .send(WebGPURequest::Submit(self.queue.0, buffer_ids))
+            .unwrap();
+    }
+}