Auto merge of #23839 - Manishearth:end-improve, r=asajeffrey

Improve session test lifecycle code

Requires https://github.com/servo/webxr/pull/25

Fixes https://github.com/servo/servo/issues/23796, hopefully

r? @asajeffrey

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components/script/dom/fakexrdevice.rs

@@ -7,13 +7,19 @@ use crate::dom::bindings::codegen::Bindings::FakeXRDeviceBinding::{
 };
 use crate::dom::bindings::codegen::Bindings::XRViewBinding::XREye;
 use crate::dom::bindings::error::{Error, Fallible};
-use crate::dom::bindings::reflector::{reflect_dom_object, Reflector};
+use crate::dom::bindings::refcounted::TrustedPromise;
+use crate::dom::bindings::reflector::{reflect_dom_object, DomObject, Reflector};
 use crate::dom::bindings::root::DomRoot;
 use crate::dom::globalscope::GlobalScope;
+use crate::dom::promise::Promise;
+use crate::task_source::TaskSource;
 use dom_struct::dom_struct;
 use euclid::{Point2D, Rect, Size2D};
 use euclid::{RigidTransform3D, Rotation3D, Transform3D, Vector3D};
 use ipc_channel::ipc::IpcSender;
+use ipc_channel::router::ROUTER;
+use profile_traits::ipc;
+use std::rc::Rc;
 use webxr_api::{MockDeviceMsg, View, Views};
 
 #[dom_struct]
@@ -139,4 +145,27 @@ impl FakeXRDeviceMethods for FakeXRDevice {
             .send(MockDeviceMsg::SetViewerOrigin(get_origin(origin)?));
         Ok(())
     }
+
+    /// https://github.com/immersive-web/webxr-test-api/blob/master/explainer.md
+    fn Disconnect(&self) -> Rc<Promise> {
+        let global = self.global();
+        let p = Promise::new(&global);
+        let mut trusted = Some(TrustedPromise::new(p.clone()));
+        let (task_source, canceller) = global
+            .as_window()
+            .task_manager()
+            .dom_manipulation_task_source_with_canceller();
+        let (sender, receiver) = ipc::channel(global.time_profiler_chan().clone()).unwrap();
+        ROUTER.add_route(
+            receiver.to_opaque(),
+            Box::new(move |_| {
+                let trusted = trusted
+                    .take()
+                    .expect("disconnect callback called multiple times");
+                let _ = task_source.queue_with_canceller(trusted.resolve_task(()), &canceller);
+            }),
+        );
+        self.disconnect(sender);
+        p
+    }
 }

components/script/dom/webidls/FakeXRDevice.webidl

@@ -26,6 +26,9 @@ interface FakeXRDevice {
 
   // Promise<FakeXRInputController>
   //     simulateInputSourceConnection(FakeXRInputSourceInit);
+
+  // behaves as if device was disconnected
+  Promise<void> disconnect();
 };
 
 // https://immersive-web.github.io/webxr/#dom-xrwebgllayer-getviewport

components/script/dom/xrtest.rs

@@ -178,9 +178,7 @@ impl XRTestMethods for XRTest {
             let mut rooted_devices: Vec<_> =
                 devices.iter().map(|x| DomRoot::from_ref(&**x)).collect();
             devices.clear();
-            for device in rooted_devices.drain(..) {
-                device.disconnect(sender.clone());
-            }
+
             let mut trusted = Some(TrustedPromise::new(p.clone()));
             let (task_source, canceller) = global
                 .as_window()
@@ -201,9 +199,9 @@ impl XRTestMethods for XRTest {
                 }),
             );
 
-            // XXXManishearth this is a hack, it will need to be replaced when
-            // we improve how mock messaging works
-            p.resolve_native(&())
+            for device in rooted_devices.drain(..) {
+                device.disconnect(sender.clone());
+            }
         };
         p
     }