Update WebXR Layer IDL, and matching changes to the Rust code.

components/script/dom/xrrenderstate.rs

@@ -4,17 +4,18 @@
 
 use crate::dom::bindings::cell::DomRefCell;
 use crate::dom::bindings::codegen::Bindings::XRRenderStateBinding::XRRenderStateMethods;
-use crate::dom::bindings::codegen::UnionTypes::XRWebGLLayerOrXRLayer as RootedXRWebGLLayerOrXRLayer;
 use crate::dom::bindings::num::Finite;
 use crate::dom::bindings::reflector::{reflect_dom_object, DomObject, Reflector};
-use crate::dom::bindings::root::{Dom, DomRoot, MutNullableDom};
+use crate::dom::bindings::root::Dom;
+use crate::dom::bindings::root::{DomRoot, MutNullableDom};
+use crate::dom::bindings::utils::to_frozen_array;
 use crate::dom::globalscope::GlobalScope;
 use crate::dom::xrlayer::XRLayer;
 use crate::dom::xrwebgllayer::XRWebGLLayer;
-use canvas_traits::webgl::WebGLContextId;
+use crate::script_runtime::JSContext;
 use dom_struct::dom_struct;
+use js::jsval::JSVal;
 use std::cell::Cell;
-use webxr_api::LayerId;
 use webxr_api::SubImages;
 
 #[dom_struct]
@@ -24,51 +25,7 @@ pub struct XRRenderState {
     depth_far: Cell<f64>,
     inline_vertical_fov: Cell<Option<f64>>,
     base_layer: MutNullableDom<XRWebGLLayer>,
-    layers: DomRefCell<Vec<XRWebGLLayerOrXRLayer>>,
-}
-
-#[unrooted_must_root_lint::must_root]
-#[derive(Clone, JSTraceable, MallocSizeOf)]
-pub enum XRWebGLLayerOrXRLayer {
-    XRWebGLLayer(Dom<XRWebGLLayer>),
-    XRLayer(Dom<XRLayer>),
-}
-
-impl XRWebGLLayerOrXRLayer {
-    #[allow(unrooted_must_root)]
-    fn from_ref(layer: &RootedXRWebGLLayerOrXRLayer) -> XRWebGLLayerOrXRLayer {
-        match layer {
-            RootedXRWebGLLayerOrXRLayer::XRWebGLLayer(ref layer) => {
-                XRWebGLLayerOrXRLayer::XRWebGLLayer(Dom::from_ref(layer))
-            },
-            RootedXRWebGLLayerOrXRLayer::XRLayer(ref layer) => {
-                XRWebGLLayerOrXRLayer::XRLayer(Dom::from_ref(layer))
-            },
-        }
-    }
-
-    pub(crate) fn layer_id(&self) -> Option<LayerId> {
-        match self {
-            XRWebGLLayerOrXRLayer::XRWebGLLayer(ref layer) => layer.layer_id(),
-            XRWebGLLayerOrXRLayer::XRLayer(ref layer) => Some(layer.layer_id()),
-        }
-    }
-}
-
-impl RootedXRWebGLLayerOrXRLayer {
-    pub(crate) fn layer_id(&self) -> Option<LayerId> {
-        match self {
-            RootedXRWebGLLayerOrXRLayer::XRWebGLLayer(ref layer) => layer.layer_id(),
-            RootedXRWebGLLayerOrXRLayer::XRLayer(ref layer) => Some(layer.layer_id()),
-        }
-    }
-
-    pub(crate) fn context_id(&self) -> WebGLContextId {
-        match self {
-            RootedXRWebGLLayerOrXRLayer::XRWebGLLayer(ref layer) => layer.context_id(),
-            RootedXRWebGLLayerOrXRLayer::XRLayer(ref layer) => layer.context_id(),
-        }
-    }
+    layers: DomRefCell<Vec<Dom<XRLayer>>>,
 }
 
 impl XRRenderState {
@@ -77,7 +34,7 @@ impl XRRenderState {
         depth_far: f64,
         inline_vertical_fov: Option<f64>,
         layer: Option<&XRWebGLLayer>,
-        layers: &[XRWebGLLayerOrXRLayer],
+        layers: Vec<&XRLayer>,
     ) -> XRRenderState {
         debug_assert!(layer.is_none() || layers.is_empty());
         XRRenderState {
@@ -86,7 +43,12 @@ impl XRRenderState {
             depth_far: Cell::new(depth_far),
             inline_vertical_fov: Cell::new(inline_vertical_fov),
             base_layer: MutNullableDom::new(layer),
-            layers: DomRefCell::new(layers.iter().cloned().collect()),
+            layers: DomRefCell::new(
+                layers
+                    .into_iter()
+                    .map(|layer| Dom::from_ref(layer))
+                    .collect(),
+            ),
         }
     }
 
@@ -96,7 +58,7 @@ impl XRRenderState {
         depth_far: f64,
         inline_vertical_fov: Option<f64>,
         layer: Option<&XRWebGLLayer>,
-        layers: &[XRWebGLLayerOrXRLayer],
+        layers: Vec<&XRLayer>,
     ) -> DomRoot<XRRenderState> {
         reflect_dom_object(
             Box::new(XRRenderState::new_inherited(
@@ -111,14 +73,13 @@ impl XRRenderState {
     }
 
     pub fn clone_object(&self) -> DomRoot<Self> {
-        let layers = self.layers.borrow();
         XRRenderState::new(
             &self.global(),
             self.depth_near.get(),
             self.depth_far.get(),
             self.inline_vertical_fov.get(),
             self.base_layer.get().as_ref().map(|x| &**x),
-            &layers,
+            self.layers.borrow().iter().map(|x| &**x).collect(),
         )
     }
 
@@ -135,12 +96,15 @@ impl XRRenderState {
     pub fn set_base_layer(&self, layer: Option<&XRWebGLLayer>) {
         self.base_layer.set(layer)
     }
-    pub fn set_layers(&self, layers: &[RootedXRWebGLLayerOrXRLayer]) {
-        *self.layers.borrow_mut() = layers.iter().map(XRWebGLLayerOrXRLayer::from_ref).collect();
+    pub fn set_layers(&self, layers: Vec<&XRLayer>) {
+        *self.layers.borrow_mut() = layers
+            .into_iter()
+            .map(|layer| Dom::from_ref(layer))
+            .collect();
     }
     pub fn with_layers<F, R>(&self, f: F) -> R
     where
-        F: FnOnce(&[XRWebGLLayerOrXRLayer]) -> R,
+        F: FnOnce(&[Dom<XRLayer>]) -> R,
     {
         let layers = self.layers.borrow();
         f(&*layers)
@@ -187,4 +151,12 @@ impl XRRenderStateMethods for XRRenderState {
     fn GetBaseLayer(&self) -> Option<DomRoot<XRWebGLLayer>> {
         self.base_layer.get()
     }
+
+    /// https://immersive-web.github.io/layers/#dom-xrrenderstate-layers
+    fn Layers(&self, cx: JSContext) -> JSVal {
+        // TODO: cache this array?
+        let layers = self.layers.borrow();
+        let layers: Vec<&XRLayer> = layers.iter().map(|x| &**x).collect();
+        to_frozen_array(&layers[..], cx)
+    }
 }