Auto merge of #22743 - ferjm:shadowdom, r=emilio

Partial ShadowDOM support

This is just an early WIP, not to take it very seriously yet.

- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [x] These changes fix #22719
- [x] There are tests for these changes

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1 files changed, 24 insertions, 1 deletions

diff --git a/components/script/dom/bindings/trace.rs b/components/script/dom/bindings/trace.rs
index f1734d74b55..56805e4d9fe 100644
--- a/components/script/dom/bindings/trace.rs
+++ b/components/script/dom/bindings/trace.rs
@@ -118,6 +118,7 @@ use std::sync::atomic::{AtomicBool, AtomicUsize};
 use std::sync::{Arc, Mutex};
 use std::time::{Instant, SystemTime};
 use style::attr::{AttrIdentifier, AttrValue, LengthOrPercentageOrAuto};
+use style::author_styles::AuthorStyles;
 use style::context::QuirksMode;
 use style::dom::OpaqueNode;
 use style::element_state::*;
@@ -125,10 +126,11 @@ use style::media_queries::MediaList;
 use style::properties::PropertyDeclarationBlock;
 use style::selector_parser::{PseudoElement, Snapshot};
 use style::shared_lock::{Locked as StyleLocked, SharedRwLock as StyleSharedRwLock};
-use style::stylesheet_set::DocumentStylesheetSet;
+use style::stylesheet_set::{AuthorStylesheetSet, DocumentStylesheetSet};
 use style::stylesheets::keyframes_rule::Keyframe;
 use style::stylesheets::{CssRules, FontFaceRule, KeyframesRule, MediaRule, Stylesheet};
 use style::stylesheets::{ImportRule, NamespaceRule, StyleRule, SupportsRule, ViewportRule};
+use style::stylist::CascadeData;
 use style::values::specified::Length;
 use tendril::fmt::UTF8;
 use tendril::stream::LossyDecoder;
@@ -497,6 +499,7 @@ unsafe_no_jsmanaged_fields!(HTMLMediaElementFetchContext);
 unsafe_no_jsmanaged_fields!(Rotation3D<f64>, Transform2D<f32>, Transform3D<f64>);
 unsafe_no_jsmanaged_fields!(Point2D<f32>, Vector2D<f32>, Rect<Au>);
 unsafe_no_jsmanaged_fields!(Rect<f32>, RigidTransform3D<f64>);
+unsafe_no_jsmanaged_fields!(CascadeData);
 
 unsafe impl<'a> JSTraceable for &'a str {
     #[inline]
@@ -715,6 +718,26 @@ where
     }
 }
 
+unsafe impl<S> JSTraceable for AuthorStylesheetSet<S>
+where
+    S: JSTraceable + ::style::stylesheets::StylesheetInDocument + PartialEq + 'static,
+{
+    unsafe fn trace(&self, tracer: *mut JSTracer) {
+        for s in self.iter() {
+            s.trace(tracer)
+        }
+    }
+}
+
+unsafe impl<S> JSTraceable for AuthorStyles<S>
+where
+    S: JSTraceable + ::style::stylesheets::StylesheetInDocument + PartialEq + 'static,
+{
+    unsafe fn trace(&self, tracer: *mut JSTracer) {
+        self.stylesheets.trace(tracer)
+    }
+}
+
 unsafe impl<Sink> JSTraceable for LossyDecoder<Sink>
 where
     Sink: JSTraceable + TendrilSink<UTF8>,