Add new Window globals as debuggees

Signed-off-by: Delan Azabani <dazabani@igalia.com>
Co-authored-by: atbrakhi <atbrakhi@igalia.com>

components/script/dom/debuggerevent.rs

@@ -0,0 +1,64 @@
+/* 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 std::default::Default;
+use std::ptr::NonNull;
+
+use dom_struct::dom_struct;
+use js::jsapi::{JSObject, Value};
+use script_bindings::conversions::SafeToJSValConvertible;
+use script_bindings::reflector::DomObject;
+
+use crate::dom::bindings::codegen::Bindings::DebuggerEventBinding::DebuggerEventMethods;
+use crate::dom::bindings::codegen::Bindings::EventBinding::Event_Binding::EventMethods;
+use crate::dom::bindings::reflector::reflect_dom_object;
+use crate::dom::bindings::root::{DomRoot, MutNullableDom};
+use crate::dom::event::Event;
+use crate::dom::types::GlobalScope;
+use crate::script_runtime::CanGc;
+
+#[dom_struct]
+/// Event for Rust → JS calls in [`crate::dom::DebuggerGlobalScope`].
+pub(crate) struct DebuggerEvent {
+    event: Event,
+    global: MutNullableDom<GlobalScope>,
+}
+
+impl DebuggerEvent {
+    pub(crate) fn new(
+        debugger_global: &GlobalScope,
+        global: &GlobalScope,
+        can_gc: CanGc,
+    ) -> DomRoot<Self> {
+        let result = Box::new(Self {
+            event: Event::new_inherited(),
+            global: Default::default(),
+        });
+        // TODO: make these fields not optional somehow?
+        result.global.set(Some(global));
+
+        result.event.init_event("addDebuggee".into(), false, false);
+
+        reflect_dom_object(result, debugger_global, can_gc)
+    }
+}
+
+impl DebuggerEventMethods<crate::DomTypeHolder> for DebuggerEvent {
+    // check-tidy: no specs after this line
+    fn Global(&self, r#cx: script_bindings::script_runtime::JSContext) -> NonNull<JSObject> {
+        // Convert the debuggee global’s reflector to a Value, wrapping it from its originating realm (debuggee realm)
+        // into the active realm (debugger realm) so that it can be passed across compartments.
+        rooted!(in(*cx) let mut result: Value);
+        self.global
+            .get()
+            .expect("Guaranteed by new")
+            .reflector()
+            .safe_to_jsval(cx, result.handle_mut());
+        NonNull::new(result.to_object()).unwrap()
+    }
+
+    fn IsTrusted(&self) -> bool {
+        self.event.IsTrusted()
+    }
+}