supportsSession() -> isSessionSupported()

components/script/dom/webidls/XR.webidl

@@ -6,7 +6,7 @@
 [SecureContext, Exposed=Window, Pref="dom.webxr.enabled"]
 interface XR: EventTarget {
   // Methods
-  Promise<void> supportsSession(XRSessionMode mode);
+  Promise<boolean> isSessionSupported(XRSessionMode mode);
   Promise<XRSession> requestSession(XRSessionMode mode, optional  XRSessionInit parameters = {});
 
   // Events

components/script/dom/xr.rs

@@ -113,8 +113,8 @@ impl Into<SessionMode> for XRSessionMode {
 }
 
 impl XRMethods for XR {
-    /// https://immersive-web.github.io/webxr/#dom-xr-supportssessionmode
-    fn SupportsSession(&self, mode: XRSessionMode) -> Rc<Promise> {
+    /// https://immersive-web.github.io/webxr/#dom-xr-issessionsupported
+    fn IsSessionSupported(&self, mode: XRSessionMode) -> Rc<Promise> {
         // XXXManishearth this should select an XR device first
         let promise = Promise::new(&self.global());
         let mut trusted = Some(TrustedPromise::new(promise.clone()));
@@ -141,10 +141,11 @@ impl XRMethods for XR {
                     return;
                 };
                 if let Ok(()) = message {
-                    let _ = task_source.queue_with_canceller(trusted.resolve_task(()), &canceller);
+                    let _ =
+                        task_source.queue_with_canceller(trusted.resolve_task(true), &canceller);
                 } else {
-                    let _ = task_source
-                        .queue_with_canceller(trusted.reject_task(Error::NotSupported), &canceller);
+                    let _ =
+                        task_source.queue_with_canceller(trusted.resolve_task(false), &canceller);
                 };
             }),
         );

tests/wpt/metadata/webxr/ar-module/xrDevice_isSessionSupported_immersive-ar.https.html.ini

@@ -1,7 +1,4 @@
 [xrDevice_isSessionSupported_immersive-ar.https.html]
-  [isSessionSupported resolves to true for immersive-ar on a supported device]
-    expected: FAIL
-
   [isSessionSupported resolves to false for immersive-ar on an unsupported device]
     expected: FAIL
 

tests/wpt/metadata/webxr/idlharness.https.window.js.ini

@@ -116,18 +116,15 @@
   [XRSession interface: operation end()]
     expected: FAIL
 
-  [XR interface: operation isSessionSupported(XRSessionMode)]
-    expected: FAIL
-
   [XR interface: calling isSessionSupported(XRSessionMode) on navigator.xr with too few arguments must throw TypeError]
     expected: FAIL
 
-  [XR interface: navigator.xr must inherit property "isSessionSupported(XRSessionMode)" with the proper type]
-    expected: FAIL
-
   [WebGLRenderingContext includes WebGLRenderingContextOverloads: member names are unique]
     expected: FAIL
 
   [WebGLRenderingContext includes WebGLRenderingContextBase: member names are unique]
     expected: FAIL
 
+  [XR interface: operation isSessionSupported(XRSessionMode)]
+    expected: FAIL
+