Make StylesheetSet an enum instead of a trait object

components/script/dom/document.rs

@@ -155,7 +155,7 @@ use style::media_queries::{Device, MediaType};
 use style::selector_parser::{RestyleDamage, Snapshot};
 use style::shared_lock::SharedRwLock as StyleSharedRwLock;
 use style::str::{split_html_space_chars, str_join};
-use style::stylesheet_set::DocumentStylesheetSet;
+use style::stylesheet_set::{DocumentStylesheetSet, StylesheetSet};
 use style::stylesheets::{Origin, OriginSet, Stylesheet};
 use url::percent_encoding::percent_decode;
 use url::Host;
@@ -4643,9 +4643,9 @@ impl StyleSheetListOwner for Dom<Document> {
             ))
             .unwrap();
 
-        self.document_or_shadow_root.add_stylesheet(
+        DocumentOrShadowRoot::add_stylesheet(
             owner,
-            stylesheets,
+            StylesheetSet::Document(stylesheets),
             sheet,
             insertion_point,
             self.style_shared_lock(),
@@ -4660,10 +4660,10 @@ impl StyleSheetListOwner for Dom<Document> {
             .send(Msg::RemoveStylesheet(s.clone()))
             .unwrap();
 
-        self.document_or_shadow_root.remove_stylesheet(
+        DocumentOrShadowRoot::remove_stylesheet(
             owner,
             s,
-            &mut *self.stylesheets.borrow_mut(),
+            StylesheetSet::Document(&mut *self.stylesheets.borrow_mut()),
         )
     }
 

components/script/dom/documentorshadowroot.rs

@@ -211,10 +211,9 @@ impl DocumentOrShadowRoot {
     /// Remove a stylesheet owned by `owner` from the list of document sheets.
     #[allow(unrooted_must_root)] // Owner needs to be rooted already necessarily.
     pub fn remove_stylesheet(
-        &self,
         owner: &Element,
         s: &Arc<Stylesheet>,
-        stylesheets: &mut StylesheetSet<StyleSheetInDocument>,
+        mut stylesheets: StylesheetSet<StyleSheetInDocument>,
     ) {
         let guard = s.shared_lock.read();
 
@@ -233,9 +232,8 @@ impl DocumentOrShadowRoot {
     /// correct tree position.
     #[allow(unrooted_must_root)] // Owner needs to be rooted already necessarily.
     pub fn add_stylesheet(
-        &self,
         owner: &Element,
-        stylesheets: &mut StylesheetSet<StyleSheetInDocument>,
+        mut stylesheets: StylesheetSet<StyleSheetInDocument>,
         sheet: Arc<Stylesheet>,
         insertion_point: Option<StyleSheetInDocument>,
         style_shared_lock: &StyleSharedRwLock,

components/script/dom/shadowroot.rs

@@ -24,6 +24,7 @@ use style::author_styles::AuthorStyles;
 use style::dom::TElement;
 use style::media_queries::Device;
 use style::shared_lock::SharedRwLockReadGuard;
+use style::stylesheet_set::StylesheetSet;
 use style::stylesheets::Stylesheet;
 
 // https://dom.spec.whatwg.org/#interface-shadowroot
@@ -219,9 +220,9 @@ impl StyleSheetListOwner for Dom<ShadowRoot> {
                     .is_before(sheet_in_shadow.owner.upcast())
             })
             .cloned();
-        self.document_or_shadow_root.add_stylesheet(
+        DocumentOrShadowRoot::add_stylesheet(
             owner,
-            stylesheets,
+            StylesheetSet::Author(stylesheets),
             sheet,
             insertion_point,
             self.document.style_shared_lock(),
@@ -231,10 +232,10 @@ impl StyleSheetListOwner for Dom<ShadowRoot> {
     /// Remove a stylesheet owned by `owner` from the list of shadow root sheets.
     #[allow(unrooted_must_root)] // Owner needs to be rooted already necessarily.
     fn remove_stylesheet(&self, owner: &Element, s: &Arc<Stylesheet>) {
-        self.document_or_shadow_root.remove_stylesheet(
+        DocumentOrShadowRoot::remove_stylesheet(
             owner,
             s,
-            &mut self.author_styles.borrow_mut().stylesheets,
+            StylesheetSet::Author(&mut self.author_styles.borrow_mut().stylesheets),
         )
     }
 

components/style/stylesheet_set.rs

@@ -374,36 +374,65 @@ where
 }
 
 /// Functionality common to DocumentStylesheetSet and AuthorStylesheetSet.
-pub trait StylesheetSet<S>
+pub enum StylesheetSet<'a, S>
+where
+    S: StylesheetInDocument + PartialEq + 'static,
+{
+    /// Author stylesheet set.
+    Author(&'a mut AuthorStylesheetSet<S>),
+    /// Document stylesheet set.
+    Document(&'a mut DocumentStylesheetSet<S>),
+}
+
+impl<'a, S> StylesheetSet<'a, S>
 where
     S: StylesheetInDocument + PartialEq + 'static,
 {
     /// Appends a new stylesheet to the current set.
     ///
     /// No device implies not computing invalidations.
-    fn append_stylesheet(
+    pub fn append_stylesheet(
         &mut self,
         device: Option<&Device>,
         sheet: S,
         guard: &SharedRwLockReadGuard,
-    );
+    ) {
+        match self {
+            StylesheetSet::Author(set) => set.append_stylesheet(device, sheet, guard),
+            StylesheetSet::Document(set) => set.append_stylesheet(device, sheet, guard),
+        }
+    }
 
     /// Insert a given stylesheet before another stylesheet in the document.
-    fn insert_stylesheet_before(
+    pub fn insert_stylesheet_before(
         &mut self,
         device: Option<&Device>,
         sheet: S,
         before_sheet: S,
         guard: &SharedRwLockReadGuard,
-    );
+    ) {
+        match self {
+            StylesheetSet::Author(set) => {
+                set.insert_stylesheet_before(device, sheet, before_sheet, guard)
+            },
+            StylesheetSet::Document(set) => {
+                set.insert_stylesheet_before(device, sheet, before_sheet, guard)
+            },
+        }
+    }
 
     /// Remove a given stylesheet from the set.
-    fn remove_stylesheet(
+    pub fn remove_stylesheet(
         &mut self,
         device: Option<&Device>,
         sheet: S,
         guard: &SharedRwLockReadGuard,
-    );
+    ) {
+        match self {
+            StylesheetSet::Author(set) => set.remove_stylesheet(device, sheet, guard),
+            StylesheetSet::Document(set) => set.remove_stylesheet(device, sheet, guard),
+        }
+    }
 }
 
 /// This macro defines methods common to DocumentStylesheetSet and
@@ -429,16 +458,11 @@ macro_rules! stylesheetset_impl {
                         .collect_invalidations_for(device, sheet, guard);
                 }
             }
-        }
 
-        impl<S> StylesheetSet<S> for $set_type
-        where
-            S: StylesheetInDocument + PartialEq + 'static,
-        {
             /// Appends a new stylesheet to the current set.
             ///
             /// No device implies not computing invalidations.
-            fn append_stylesheet(
+            pub fn append_stylesheet(
                 &mut self,
                 device: Option<&Device>,
                 sheet: S,
@@ -451,7 +475,7 @@ macro_rules! stylesheetset_impl {
             }
 
             /// Insert a given stylesheet before another stylesheet in the document.
-            fn insert_stylesheet_before(
+            pub fn insert_stylesheet_before(
                 &mut self,
                 device: Option<&Device>,
                 sheet: S,
@@ -466,7 +490,7 @@ macro_rules! stylesheetset_impl {
             }
 
             /// Remove a given stylesheet from the set.
-            fn remove_stylesheet(
+            pub fn remove_stylesheet(
                 &mut self,
                 device: Option<&Device>,
                 sheet: S,