servo: Merge #17102 - Animation only restyle fix (from hiikezoe:animation-only-restyle-fix); r=heycam

<!-- Please describe your changes on the following line: -->
This is a PR  for https://bugzilla.mozilla.org/show_bug.cgi?id=1361938
---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: -->
- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes do not require tests because it's for stylo

Source-Repo: https://github.com/servo/servo
Source-Revision: 31c7198f71550995066de6673af749472f083121

--HG--
extra : subtree_source : https%3A//hg.mozilla.org/projects/converted-servo-linear
extra : subtree_revision : d2c75c73e215732279474138e66c73ea3acc3c84

servo/components/style/dom.rs

@@ -329,6 +329,11 @@ pub trait TElement : Eq + PartialEq + Debug + Hash + Sized + Copy + Clone +
     /// Get this element's style attribute.
     fn style_attribute(&self) -> Option<&Arc<Locked<PropertyDeclarationBlock>>>;
 
+    /// Unset the style attribute's dirty bit.
+    /// Servo doesn't need to manage ditry bit for style attribute.
+    fn unset_dirty_style_attribute(&self) {
+    }
+
     /// Get this element's SMIL override declarations.
     fn get_smil_override(&self) -> Option<&Arc<Locked<PropertyDeclarationBlock>>> {
         None

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

@@ -7,6 +7,7 @@ type nsAString_internal = nsAString;
 use gecko_bindings::structs::mozilla::css::GridTemplateAreasValue;
 use gecko_bindings::structs::mozilla::css::ImageValue;
 use gecko_bindings::structs::mozilla::css::URLValue;
+use gecko_bindings::structs::mozilla::MallocSizeOf;
 use gecko_bindings::structs::mozilla::Side;
 use gecko_bindings::structs::RawGeckoAnimationPropertySegment;
 use gecko_bindings::structs::RawGeckoComputedTiming;
@@ -39,7 +40,6 @@ use gecko_bindings::structs::FontSizePrefs;
 use gecko_bindings::structs::GeckoFontMetrics;
 use gecko_bindings::structs::IterationCompositeOperation;
 use gecko_bindings::structs::Keyframe;
-use gecko_bindings::structs::MallocSizeOf;
 use gecko_bindings::structs::ServoBundledURI;
 use gecko_bindings::structs::ServoElementSnapshot;
 use gecko_bindings::structs::ServoElementSnapshotTable;
@@ -681,6 +681,9 @@ extern "C" {
                                                   RawGeckoElementBorrowed)
      -> RawServoDeclarationBlockStrongBorrowedOrNull;
 }
+extern "C" {
+    pub fn Gecko_UnsetDirtyStyleAttr(element: RawGeckoElementBorrowed);
+}
 extern "C" {
     pub fn Gecko_GetHTMLPresentationAttrDeclarationBlock(element:
                                                              RawGeckoElementBorrowed)
@@ -1764,7 +1767,8 @@ extern "C" {
 }
 extern "C" {
     pub fn Servo_StyleSheet_SizeOfIncludingThis(malloc_size_of: MallocSizeOf,
-                                                sheet: RawServoStyleSheetBorrowed)
+                                                sheet:
+                                                    RawServoStyleSheetBorrowed)
      -> usize;
 }
 extern "C" {

servo/components/style/gecko/wrapper.rs

@@ -43,6 +43,7 @@ use gecko_bindings::bindings::Gecko_GetStyleAttrDeclarationBlock;
 use gecko_bindings::bindings::Gecko_GetStyleContext;
 use gecko_bindings::bindings::Gecko_IsSignificantChild;
 use gecko_bindings::bindings::Gecko_MatchStringArgPseudo;
+use gecko_bindings::bindings::Gecko_UnsetDirtyStyleAttr;
 use gecko_bindings::bindings::Gecko_UpdateAnimations;
 use gecko_bindings::structs;
 use gecko_bindings::structs::{RawGeckoElement, RawGeckoNode};
@@ -628,6 +629,14 @@ impl<'le> TElement for GeckoElement<'le> {
         declarations.map_or(None, |s| s.as_arc_opt())
     }
 
+    fn unset_dirty_style_attribute(&self) {
+        if !self.may_have_style_attribute() {
+            return;
+        }
+
+        unsafe { Gecko_UnsetDirtyStyleAttr(self.0) };
+    }
+
     fn get_smil_override(&self) -> Option<&Arc<Locked<PropertyDeclarationBlock>>> {
         let declarations = unsafe { Gecko_GetSMILOverrideDeclarationBlock(self.0) };
         declarations.map(|s| s.as_arc_opt()).unwrap_or(None)

servo/components/style/matching.rs

@@ -1019,6 +1019,7 @@ pub trait MatchMethods : TElement {
                                                  &mut matching_context,
                                                  &mut set_selector_flags);
         }
+        self.unset_dirty_style_attribute();
 
         let primary_rule_node = stylist.rule_tree().compute_rule_node(
             &mut applicable_declarations,
@@ -1253,8 +1254,10 @@ pub trait MatchMethods : TElement {
         let mut result = false;
         result |= self.replace_rules_internal(replacements, context, data,
                                               CascadeVisitedMode::Unvisited);
-        result |= self.replace_rules_internal(replacements, context, data,
-                                              CascadeVisitedMode::Visited);
+        if !context.shared.traversal_flags.for_animation_only() {
+            result |= self.replace_rules_internal(replacements, context, data,
+                                                  CascadeVisitedMode::Visited);
+        }
         result
     }
 
@@ -1301,6 +1304,7 @@ pub trait MatchMethods : TElement {
                 result |= replace_rule_node(CascadeLevel::StyleAttributeImportant,
                                             style_attribute,
                                             primary_rules);
+                self.unset_dirty_style_attribute();
             }
             return result;
         }