servo: Merge #18571 - Add a geckolib API to check for primary style reuse (from bholley:primary_reuse_api); r=emilio

https://bugzilla.mozilla.org/show_bug.cgi?id=1401317

Source-Repo: https://github.com/servo/servo
Source-Revision: 3cea16e18f125e3839af4dd3f064b4194fde4953

--HG--
extra : subtree_source : https%3A//hg.mozilla.org/projects/converted-servo-linear
extra : subtree_revision : d3e71cc94e07434947e7950699d2486e9c32fd9f

servo/components/style/gecko/generated/bindings.rs

@@ -1936,6 +1936,11 @@ extern "C" {
     pub fn Servo_Element_IsDisplayNone(element: RawGeckoElementBorrowed)
      -> bool;
 }
+extern "C" {
+    pub fn Servo_Element_IsPrimaryStyleReusedViaRuleNode(element:
+                                                             RawGeckoElementBorrowed)
+     -> bool;
+}
 extern "C" {
     pub fn Servo_StyleSheet_FromUTF8Bytes(loader: *mut Loader,
                                           gecko_stylesheet:

servo/components/style/sharing/mod.rs

@@ -745,11 +745,16 @@ impl<E: TElement> StyleSharingCache<E> {
     /// Attempts to find an element in the cache with the given primary rule node and parent.
     pub fn lookup_by_rules(
         &mut self,
+        shared_context: &SharedStyleContext,
         inherited: &ComputedValues,
         rules: &StrongRuleNode,
         visited_rules: Option<&StrongRuleNode>,
         target: E,
     ) -> Option<PrimaryStyle> {
+        if shared_context.options.disable_style_sharing_cache {
+            return None;
+        }
+
         self.cache_mut().lookup(|candidate| {
             debug_assert_ne!(candidate.element, target);
             if !candidate.parent_style_identity().eq(inherited) {

servo/components/style/style_resolver.rs

@@ -195,6 +195,7 @@ where
 
         if may_reuse {
             let cached = self.context.thread_local.sharing_cache.lookup_by_rules(
+                self.context.shared,
                 parent_style.unwrap(),
                 inputs.rules.as_ref().unwrap(),
                 inputs.visited_rules.as_ref(),

servo/ports/geckolib/glue.rs

@@ -18,7 +18,7 @@ use std::ptr;
 use style::applicable_declarations::ApplicableDeclarationBlock;
 use style::context::{CascadeInputs, QuirksMode, SharedStyleContext, StyleContext};
 use style::context::ThreadLocalStyleContext;
-use style::data::ElementStyles;
+use style::data::{ElementStyles, self};
 use style::dom::{ShowSubtreeData, TElement, TNode};
 use style::driver;
 use style::element_state::ElementState;
@@ -842,13 +842,20 @@ pub extern "C" fn Servo_Element_GetPseudoComputedValues(element: RawGeckoElement
 }
 
 #[no_mangle]
-pub extern "C" fn Servo_Element_IsDisplayNone(element: RawGeckoElementBorrowed) -> bool
-{
+pub extern "C" fn Servo_Element_IsDisplayNone(element: RawGeckoElementBorrowed) -> bool {
     let element = GeckoElement(element);
     let data = element.borrow_data().expect("Invoking Servo_Element_IsDisplayNone on unstyled element");
     data.styles.is_display_none()
 }
 
+#[no_mangle]
+pub extern "C" fn Servo_Element_IsPrimaryStyleReusedViaRuleNode(element: RawGeckoElementBorrowed) -> bool {
+    let element = GeckoElement(element);
+    let data = element.borrow_data()
+                      .expect("Invoking Servo_Element_IsPrimaryStyleReusedViaRuleNode on unstyled element");
+    data.flags.contains(data::PRIMARY_STYLE_REUSED_VIA_RULE_NODE)
+}
+
 #[no_mangle]
 pub extern "C" fn Servo_StyleSheet_Empty(mode: SheetParsingMode) -> RawServoStyleSheetContentsStrong {
     let global_style_data = &*GLOBAL_STYLE_DATA;