script: stub AbortSignal (#37033)

This is a stub for `AbortSignal`, which we would like to merge first in
order to work in parallel on
https://github.com/servo/servo/issues/34866, and perhaps also
https://github.com/servo/servo/issues/36936

---------

Signed-off-by: gterzian <2792687+gterzian@users.noreply.github.com>
Signed-off-by: Taym Haddadi <haddadi.taym@gmail.com>
Co-authored-by: Taym Haddadi <haddadi.taym@gmail.com>

components/script/dom/abortsignal.rs

@@ -0,0 +1,71 @@
+/* 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 dom_struct::dom_struct;
+use js::jsapi::Heap;
+use js::jsval::JSVal;
+use js::rust::{HandleObject, MutableHandleValue};
+
+use crate::dom::bindings::codegen::Bindings::AbortSignalBinding::AbortSignalMethods;
+use crate::dom::bindings::reflector::reflect_dom_object_with_proto;
+use crate::dom::bindings::root::DomRoot;
+use crate::dom::eventtarget::EventTarget;
+use crate::dom::globalscope::GlobalScope;
+use crate::script_runtime::{CanGc, JSContext};
+
+/// <https://dom.spec.whatwg.org/#abortsignal>
+#[dom_struct]
+pub(crate) struct AbortSignal {
+    eventtarget: EventTarget,
+
+    /// <https://dom.spec.whatwg.org/#abortsignal-abort-reason>
+    #[ignore_malloc_size_of = "mozjs"]
+    abort_reason: Heap<JSVal>,
+}
+
+impl AbortSignal {
+    #[allow(dead_code)]
+    fn new_inherited() -> AbortSignal {
+        AbortSignal {
+            eventtarget: EventTarget::new_inherited(),
+            abort_reason: Default::default(),
+        }
+    }
+
+    #[allow(dead_code)]
+    fn new_with_proto(
+        global: &GlobalScope,
+        proto: Option<HandleObject>,
+        can_gc: CanGc,
+    ) -> DomRoot<AbortSignal> {
+        reflect_dom_object_with_proto(
+            Box::new(AbortSignal::new_inherited()),
+            global,
+            proto,
+            can_gc,
+        )
+    }
+}
+
+impl AbortSignalMethods<crate::DomTypeHolder> for AbortSignal {
+    /// <https://dom.spec.whatwg.org/#dom-abortsignal-aborted>
+    fn Aborted(&self) -> bool {
+        // TODO
+        false
+    }
+
+    /// <https://dom.spec.whatwg.org/#dom-abortsignal-reason>
+    fn Reason(&self, _: JSContext, _rval: MutableHandleValue) {
+        // TODO
+    }
+
+    /// <https://dom.spec.whatwg.org/#dom-abortsignal-throwifaborted>
+    #[allow(unsafe_code)]
+    fn ThrowIfAborted(&self) {
+        // TODO
+    }
+
+    // <https://dom.spec.whatwg.org/#dom-abortsignal-onabort>
+    event_handler!(abort, GetOnabort, SetOnabort);
+}