script: Implement DocumentOrShadowDOM.adoptedStylesheet with FrozenArray (#38163)

Spec:
https://drafts.csswg.org/cssom/#dom-documentorshadowroot-adoptedstylesheets

Implement `DocumentOrShadowDOM.adoptedStylesheet`. Due to
`ObservableArray` being a massive issue on its own, it will be as it was
a `FrozenArray` at first. This approach is similar to how Gecko
implement adopted stylesheet. See
https://phabricator.services.mozilla.com/D144547#change-IXyOzxxFn8sU.

All of the changes will be gated behind a preference
`dom_adoptedstylesheet_enabled`.

Adopted stylesheet is implemented by adding the setter and getter of it.
While the getter works like a normal attribute getter, the setter need
to consider the inner working of document and shadow root StylesheetSet,
specifically the ordering and the invalidations. Particularly for
setter, we will clear all of the adopted stylesheet within the
StylesheetSet and readd them. Possible optimization exist, but the focus
should be directed to implementing `ObservableArray`.

More context about the implementations
https://hackmd.io/vtJAn4UyS_O0Idvk5dCO_w.

Testing: Existing WPT Coverage
Fixes: https://github.com/servo/servo/issues/37561

---------

Signed-off-by: Jo Steven Novaryo <jo.steven.novaryo@huawei.com>

components/script/dom/cssstylesheet.rs

@@ -6,6 +6,7 @@ use std::cell::Cell;
 
 use dom_struct::dom_struct;
 use js::rust::HandleObject;
+use script_bindings::root::Dom;
 use servo_arc::Arc;
 use style::media_queries::MediaList as StyleMediaList;
 use style::shared_lock::SharedRwLock;
@@ -13,6 +14,7 @@ use style::stylesheets::{
     AllowImportRules, CssRuleTypes, Origin, Stylesheet as StyleStyleSheet, UrlExtraData,
 };
 
+use crate::dom::bindings::cell::DomRefCell;
 use crate::dom::bindings::codegen::Bindings::CSSStyleSheetBinding::{
     CSSStyleSheetInit, CSSStyleSheetMethods,
 };
@@ -26,23 +28,41 @@ use crate::dom::bindings::reflector::{
 use crate::dom::bindings::root::{DomRoot, MutNullableDom};
 use crate::dom::bindings::str::{DOMString, USVString};
 use crate::dom::cssrulelist::{CSSRuleList, RulesSource};
+use crate::dom::document::Document;
 use crate::dom::element::Element;
 use crate::dom::medialist::MediaList;
 use crate::dom::node::NodeTraits;
 use crate::dom::stylesheet::StyleSheet;
+use crate::dom::stylesheetlist::StyleSheetListOwner;
 use crate::dom::window::Window;
 use crate::script_runtime::CanGc;
 
 #[dom_struct]
 pub(crate) struct CSSStyleSheet {
     stylesheet: StyleSheet,
-    owner: MutNullableDom<Element>,
+
+    /// <https://drafts.csswg.org/cssom/#concept-css-style-sheet-owner-node>
+    owner_node: MutNullableDom<Element>,
+
+    /// <https://drafts.csswg.org/cssom/#ref-for-concept-css-style-sheet-css-rules>
     rulelist: MutNullableDom<CSSRuleList>,
+
+    /// The inner Stylo's [Stylesheet].
     #[ignore_malloc_size_of = "Arc"]
     #[no_trace]
     style_stylesheet: Arc<StyleStyleSheet>,
+
+    /// <https://drafts.csswg.org/cssom/#concept-css-style-sheet-origin-clean-flag>
     origin_clean: Cell<bool>,
-    is_constructed: bool,
+
+    /// In which [Document] that this stylesheet was constructed.
+    ///
+    /// <https://drafts.csswg.org/cssom/#concept-css-style-sheet-constructor-document>
+    constructor_document: Option<Dom<Document>>,
+
+    /// Documents or shadow DOMs thats adopt this stylesheet, they will be notified whenever
+    /// the stylesheet is modified.
+    adopters: DomRefCell<Vec<StyleSheetListOwner>>,
 }
 
 impl CSSStyleSheet {
@@ -52,15 +72,16 @@ impl CSSStyleSheet {
         href: Option<DOMString>,
         title: Option<DOMString>,
         stylesheet: Arc<StyleStyleSheet>,
-        is_constructed: bool,
+        constructor_document: Option<&Document>,
     ) -> CSSStyleSheet {
         CSSStyleSheet {
             stylesheet: StyleSheet::new_inherited(type_, href, title),
-            owner: MutNullableDom::new(owner),
+            owner_node: MutNullableDom::new(owner),
             rulelist: MutNullableDom::new(None),
             style_stylesheet: stylesheet,
             origin_clean: Cell::new(true),
-            is_constructed,
+            constructor_document: constructor_document.map(Dom::from_ref),
+            adopters: Default::default(),
         }
     }
 
@@ -73,7 +94,7 @@ impl CSSStyleSheet {
         href: Option<DOMString>,
         title: Option<DOMString>,
         stylesheet: Arc<StyleStyleSheet>,
-        is_constructed: bool,
+        constructor_document: Option<&Document>,
         can_gc: CanGc,
     ) -> DomRoot<CSSStyleSheet> {
         reflect_dom_object(
@@ -83,7 +104,7 @@ impl CSSStyleSheet {
                 href,
                 title,
                 stylesheet,
-                is_constructed,
+                constructor_document,
             )),
             window,
             can_gc,
@@ -100,7 +121,7 @@ impl CSSStyleSheet {
         href: Option<DOMString>,
         title: Option<DOMString>,
         stylesheet: Arc<StyleStyleSheet>,
-        is_constructed: bool,
+        constructor_document: Option<&Document>,
         can_gc: CanGc,
     ) -> DomRoot<CSSStyleSheet> {
         reflect_dom_object_with_proto(
@@ -110,7 +131,7 @@ impl CSSStyleSheet {
                 href,
                 title,
                 stylesheet,
-                is_constructed,
+                constructor_document,
             )),
             window,
             proto,
@@ -134,21 +155,18 @@ impl CSSStyleSheet {
         self.style_stylesheet.disabled()
     }
 
-    pub(crate) fn get_owner(&self) -> Option<DomRoot<Element>> {
-        self.owner.get()
+    pub(crate) fn owner_node(&self) -> Option<DomRoot<Element>> {
+        self.owner_node.get()
     }
 
     pub(crate) fn set_disabled(&self, disabled: bool) {
-        if self.style_stylesheet.set_disabled(disabled) && self.get_owner().is_some() {
-            self.get_owner()
-                .unwrap()
-                .stylesheet_list_owner()
-                .invalidate_stylesheets();
+        if self.style_stylesheet.set_disabled(disabled) {
+            self.notify_invalidations();
         }
     }
 
-    pub(crate) fn set_owner(&self, value: Option<&Element>) {
-        self.owner.set(value);
+    pub(crate) fn set_owner_node(&self, value: Option<&Element>) {
+        self.owner_node.set(value);
     }
 
     pub(crate) fn shared_lock(&self) -> &SharedRwLock {
@@ -159,6 +177,10 @@ impl CSSStyleSheet {
         &self.style_stylesheet
     }
 
+    pub(crate) fn style_stylesheet_arc(&self) -> &Arc<StyleStyleSheet> {
+        &self.style_stylesheet
+    }
+
     pub(crate) fn set_origin_clean(&self, origin_clean: bool) {
         self.origin_clean.set(origin_clean);
     }
@@ -175,7 +197,39 @@ impl CSSStyleSheet {
     /// <https://drafts.csswg.org/cssom/#concept-css-style-sheet-constructed-flag>
     #[inline]
     pub(crate) fn is_constructed(&self) -> bool {
-        self.is_constructed
+        self.constructor_document.is_some()
+    }
+
+    pub(crate) fn constructor_document_matches(&self, other_doc: &Document) -> bool {
+        match &self.constructor_document {
+            Some(doc) => *doc == other_doc,
+            None => false,
+        }
+    }
+
+    /// Add a [StyleSheetListOwner] as an adopter to be notified whenever this stylesheet is
+    /// modified.
+    #[cfg_attr(crown, allow(crown::unrooted_must_root))]
+    pub(crate) fn add_adopter(&self, owner: StyleSheetListOwner) {
+        debug_assert!(self.is_constructed());
+        self.adopters.borrow_mut().push(owner);
+    }
+
+    pub(crate) fn remove_adopter(&self, owner: &StyleSheetListOwner) {
+        let adopters = &mut *self.adopters.borrow_mut();
+        if let Some(index) = adopters.iter().position(|o| o == owner) {
+            adopters.swap_remove(index);
+        }
+    }
+
+    /// Invalidate all stylesheet set this stylesheet is a part on.
+    pub(crate) fn notify_invalidations(&self) {
+        if let Some(owner) = self.owner_node() {
+            owner.stylesheet_list_owner().invalidate_stylesheets();
+        }
+        for adopter in self.adopters.borrow().iter() {
+            adopter.invalidate_stylesheets();
+        }
     }
 }
 
@@ -218,7 +272,7 @@ impl CSSStyleSheetMethods<crate::DomTypeHolder> for CSSStyleSheet {
             None, // href
             None, // title
             stylesheet,
-            true, // is_constructed
+            Some(&window.Document()), // constructor_document
             can_gc,
         )
     }
@@ -294,7 +348,7 @@ impl CSSStyleSheetMethods<crate::DomTypeHolder> for CSSStyleSheet {
     /// <https://drafts.csswg.org/cssom/#synchronously-replace-the-rules-of-a-cssstylesheet>
     fn ReplaceSync(&self, text: USVString) -> Result<(), Error> {
         // Step 1. If the constructed flag is not set throw a NotAllowedError
-        if !self.is_constructed {
+        if !self.is_constructed() {
             return Err(Error::NotAllowed);
         }
 
@@ -316,6 +370,9 @@ impl CSSStyleSheetMethods<crate::DomTypeHolder> for CSSStyleSheet {
         // at the next getter access.
         self.rulelist.set(None);
 
+        // Notify invalidation to update the styles immediately.
+        self.notify_invalidations();
+
         Ok(())
     }
 }