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, 12 insertions, 7 deletions

diff --git a/components/script/dom/htmlmetaelement.rs b/components/script/dom/htmlmetaelement.rs
index a8e829c3d1c..11b5706516d 100644
--- a/components/script/dom/htmlmetaelement.rs
+++ b/components/script/dom/htmlmetaelement.rs
@@ -15,7 +15,10 @@ use crate::dom::document::Document;
 use crate::dom::element::{AttributeMutation, Element};
 use crate::dom::htmlelement::HTMLElement;
 use crate::dom::htmlheadelement::HTMLHeadElement;
-use crate::dom::node::{document_from_node, window_from_node, Node, UnbindContext};
+use crate::dom::node::{
+    document_from_node, stylesheets_owner_from_node, window_from_node, BindContext, Node,
+    UnbindContext,
+};
 use crate::dom::virtualmethods::VirtualMethods;
 use dom_struct::dom_struct;
 use html5ever::{LocalName, Prefix};
@@ -97,6 +100,7 @@ impl HTMLMetaElement {
         }
     }
 
+    #[allow(unrooted_must_root)]
     fn apply_viewport(&self) {
         if !pref!(layout.viewport.enabled) {
             return;
@@ -106,6 +110,7 @@ impl HTMLMetaElement {
             let content = content.value();
             if !content.is_empty() {
                 if let Some(translated_rule) = ViewportRule::from_meta(&**content) {
+                    let stylesheets_owner = stylesheets_owner_from_node(self);
                     let document = document_from_node(self);
                     let shared_lock = document.style_shared_lock();
                     let rule = CssRule::Viewport(Arc::new(shared_lock.wrap(translated_rule)));
@@ -124,7 +129,7 @@ impl HTMLMetaElement {
                         disabled: AtomicBool::new(false),
                     });
                     *self.stylesheet.borrow_mut() = Some(sheet.clone());
-                    document.add_stylesheet(self.upcast(), sheet);
+                    stylesheets_owner.add_stylesheet(self.upcast(), sheet);
                 }
             }
         }
@@ -171,12 +176,12 @@ impl VirtualMethods for HTMLMetaElement {
         Some(self.upcast::<HTMLElement>() as &dyn VirtualMethods)
     }
 
-    fn bind_to_tree(&self, tree_in_doc: bool) {
+    fn bind_to_tree(&self, context: &BindContext) {
         if let Some(ref s) = self.super_type() {
-            s.bind_to_tree(tree_in_doc);
+            s.bind_to_tree(context);
         }
 
-        if tree_in_doc {
+        if context.tree_connected {
             self.process_attributes();
         }
     }
@@ -204,11 +209,11 @@ impl VirtualMethods for HTMLMetaElement {
             s.unbind_from_tree(context);
         }
 
-        if context.tree_in_doc {
+        if context.tree_connected {
             self.process_referrer_attribute();
 
             if let Some(s) = self.stylesheet.borrow_mut().take() {
-                document_from_node(self).remove_stylesheet(self.upcast(), &s);
+                stylesheets_owner_from_node(self).remove_stylesheet(self.upcast(), &s);
             }
         }
     }