Auto merge of #22953 - asajeffrey:webvr-glwindow, r=paulrouget

Use a test VRDisplay that renders to a GL window

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Add a `dom.webvr.test` pref that registers a new VR display, which registers to a GL window.

The matching webvr PR is https://github.com/servo/rust-webvr/pull/66.

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- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #22795
- [X] These changes do not require tests because we need a followup PR to support reftests which use the VR display

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ports/libsimpleservo/api/src/lib.rs

@@ -21,7 +21,7 @@ use servo::script_traits::{TouchEventType, TouchId};
 use servo::servo_config::opts;
 use servo::servo_config::prefs::{PrefValue, PREFS};
 use servo::servo_url::ServoUrl;
-use servo::webvr::{VRExternalShmemPtr, VRServiceManager};
+use servo::webvr::{VRExternalShmemPtr, VRMainThreadHeartbeat, VRServiceManager};
 use servo::{self, gl, webrender_api, BrowserId, Servo};
 use std::cell::{Cell, RefCell};
 use std::mem;
@@ -576,7 +576,11 @@ impl WindowMethods for ServoCallbacks {
         }
     }
 
-    fn register_vr_services(&self, services: &mut VRServiceManager) {
+    fn register_vr_services(
+        &self,
+        services: &mut VRServiceManager,
+        _: &mut Vec<Box<VRMainThreadHeartbeat>>,
+    ) {
         if let Some(ptr) = self.vr_pointer {
             services.register_vrexternal(VRExternalShmemPtr::new(ptr));
         }