Add an FFI to check that a given (pseudo-) element has any type of animations or not.

If an element has any type of animations in match_elements(), we need to call
UpdateEffectProperties() to update KeyframeEffectReadOnly::mProperties.

components/script/layout_wrapper.rs

@@ -455,6 +455,10 @@ impl<'le> TElement for ServoLayoutElement<'le> {
         panic!("this should be only called on gecko");
     }
 
+    fn has_animations(&self, _pseudo: Option<&PseudoElement>) -> bool {
+        panic!("this should be only called on gecko");
+    }
+
     fn has_css_animations(&self, _pseudo: Option<&PseudoElement>) -> bool {
         panic!("this should be only called on gecko");
     }

components/style/dom.rs

@@ -370,6 +370,11 @@ pub trait TElement : PartialEq + Debug + Sized + Copy + Clone + ElementExt + Pre
     /// Note: Gecko only.
     fn update_animations(&self, _pseudo: Option<&PseudoElement>);
 
+    /// Returns true if the element has relevant animations. Relevant
+    /// animations are those animations that are affecting the element's style
+    /// or are scheduled to do so in the future.
+    fn has_animations(&self, _pseudo: Option<&PseudoElement>) -> bool;
+
     /// Returns true if the element has a CSS animation.
     fn has_css_animations(&self, _pseudo: Option<&PseudoElement>) -> bool;
 

components/style/gecko/wrapper.rs

@@ -30,6 +30,7 @@ use gecko_bindings::bindings::{Gecko_IsLink, Gecko_IsRootElement, Gecko_MatchesE
 use gecko_bindings::bindings::{Gecko_IsUnvisitedLink, Gecko_IsVisitedLink, Gecko_Namespace};
 use gecko_bindings::bindings::{Gecko_SetNodeFlags, Gecko_UnsetNodeFlags};
 use gecko_bindings::bindings::Gecko_ClassOrClassList;
+use gecko_bindings::bindings::Gecko_ElementHasAnimations;
 use gecko_bindings::bindings::Gecko_ElementHasCSSAnimations;
 use gecko_bindings::bindings::Gecko_GetAnimationRule;
 use gecko_bindings::bindings::Gecko_GetHTMLPresentationAttrDeclarationBlock;
@@ -587,6 +588,11 @@ impl<'le> TElement for GeckoElement<'le> {
         }
     }
 
+    fn has_animations(&self, pseudo: Option<&PseudoElement>) -> bool {
+        let atom_ptr = PseudoElement::ns_atom_or_null_from_opt(pseudo);
+        unsafe { Gecko_ElementHasAnimations(self.0, atom_ptr) }
+    }
+
     fn has_css_animations(&self, pseudo: Option<&PseudoElement>) -> bool {
         let atom_ptr = PseudoElement::ns_atom_or_null_from_opt(pseudo);
         unsafe { Gecko_ElementHasCSSAnimations(self.0, atom_ptr) }

components/style/gecko_bindings/bindings.rs

@@ -612,6 +612,10 @@ extern "C" {
                                   aParentComputedValues:
                                       ServoComputedValuesBorrowedOrNull);
 }
+extern "C" {
+    pub fn Gecko_ElementHasAnimations(aElement: RawGeckoElementBorrowed,
+                                      aPseudoTagOrNull: *mut nsIAtom) -> bool;
+}
 extern "C" {
     pub fn Gecko_ElementHasCSSAnimations(aElement: RawGeckoElementBorrowed,
                                          aPseudoTagOrNull: *mut nsIAtom)