--- a/layout/style/ServoBindingTypes.h
+++ b/layout/style/ServoBindingTypes.h
@@ -24,16 +24,18 @@ namespace mozilla {
   struct StyleAnimation;
 namespace css {
 struct URLExtraData;
 } // namespace css
 namespace dom {
 class Element;
 class StyleChildrenIterator;
 } // namespace dom
+struct AnimationPropertySegment;
+struct ComputedTiming;
 struct Keyframe;
 struct PropertyStyleAnimationValuePair;
 using ComputedKeyframeValues = nsTArray<PropertyStyleAnimationValuePair>;
 } // namespace mozilla
 
 class nsCSSValue;
 struct nsFontFaceRuleContainer;
 class nsIDocument;
@@ -49,16 +51,18 @@ typedef mozilla::dom::Element RawGeckoEl
 typedef nsIDocument RawGeckoDocument;
 typedef nsPresContext RawGeckoPresContext;
 typedef mozilla::css::URLExtraData RawGeckoURLExtraData;
 typedef nsTArray<mozilla::Keyframe> RawGeckoKeyframeList;
 typedef nsTArray<mozilla::ComputedKeyframeValues> RawGeckoComputedKeyframeValuesList;
 typedef nsTArray<mozilla::PropertyStyleAnimationValuePair> RawGeckoAnimationValueList;
 typedef nsStyleAutoArray<mozilla::StyleAnimation> RawGeckoStyleAnimationList;
 typedef nsTArray<nsFontFaceRuleContainer> RawGeckoFontFaceRuleList;
+typedef mozilla::AnimationPropertySegment RawGeckoAnimationPropertySegment;
+typedef mozilla::ComputedTiming RawGeckoComputedTiming;
 
 // We have these helper types so that we can directly generate
 // things like &T or Borrowed<T> on the Rust side in the function, providing
 // additional safety benefits.
 //
 // FFI has a problem with templated types, so we just use raw pointers here.
 //
 // The "Borrowed" types generate &T or Borrowed<T> in the nullable case.
@@ -126,16 +130,18 @@ DECL_BORROWED_REF_TYPE_FOR(RawGeckoPresC
 DECL_BORROWED_MUT_REF_TYPE_FOR(RawGeckoAnimationValueList)
 DECL_BORROWED_MUT_REF_TYPE_FOR(RawGeckoKeyframeList)
 DECL_BORROWED_REF_TYPE_FOR(RawGeckoKeyframeList)
 DECL_BORROWED_MUT_REF_TYPE_FOR(RawGeckoComputedKeyframeValuesList)
 DECL_BORROWED_REF_TYPE_FOR(RawGeckoStyleAnimationList)
 DECL_BORROWED_MUT_REF_TYPE_FOR(nsTimingFunction)
 DECL_BORROWED_REF_TYPE_FOR(nsTimingFunction)
 DECL_BORROWED_MUT_REF_TYPE_FOR(RawGeckoFontFaceRuleList)
+DECL_BORROWED_REF_TYPE_FOR(RawGeckoAnimationPropertySegment)
+DECL_BORROWED_REF_TYPE_FOR(RawGeckoComputedTiming)
 
 #undef DECL_ARC_REF_TYPE_FOR
 #undef DECL_OWNED_REF_TYPE_FOR
 #undef DECL_NULLABLE_OWNED_REF_TYPE_FOR
 #undef DECL_BORROWED_REF_TYPE_FOR
 #undef DECL_NULLABLE_BORROWED_REF_TYPE_FOR
 #undef DECL_BORROWED_MUT_REF_TYPE_FOR
 #undef DECL_NULLABLE_BORROWED_MUT_REF_TYPE_FOR

--- a/layout/style/ServoBindings.cpp
+++ b/layout/style/ServoBindings.cpp
@@ -508,16 +508,38 @@ Gecko_ElementHasCSSAnimations(RawGeckoEl
                                        CSSEnabledState::eForAllContent);
   nsAnimationManager::CSSAnimationCollection* collection =
     nsAnimationManager::CSSAnimationCollection
                       ::GetAnimationCollection(aElement, pseudoType);
 
   return collection && !collection->mAnimations.IsEmpty();
 }
 
+double
+Gecko_GetProgressFromComputedTiming(RawGeckoComputedTimingBorrowed aComputedTiming)
+{
+  return aComputedTiming->mProgress.Value();
+}
+
+double
+Gecko_GetPositionInSegment(RawGeckoAnimationPropertySegmentBorrowed aSegment,
+                          double aProgress,
+                          ComputedTimingFunction::BeforeFlag aBeforeFlag)
+{
+  MOZ_ASSERT(aSegment->mFromKey < aSegment->mToKey,
+             "The segment from key should be less than to key");
+
+  double positionInSegment =
+    (aProgress - aSegment->mFromKey) / (aSegment->mToKey - aSegment->mFromKey);
+
+  return ComputedTimingFunction::GetPortion(aSegment->mTimingFunction,
+                                            positionInSegment,
+                                            aBeforeFlag);
+}
+
 void
 Gecko_FillAllBackgroundLists(nsStyleImageLayers* aLayers, uint32_t aMaxLen)
 {
   nsRuleNode::FillAllBackgroundLists(*aLayers, aMaxLen);
 }
 
 void
 Gecko_FillAllMaskLists(nsStyleImageLayers* aLayers, uint32_t aMaxLen)

--- a/layout/style/ServoBindings.h
+++ b/layout/style/ServoBindings.h
@@ -9,16 +9,17 @@
 
 #include <stdint.h>
 
 #include "mozilla/ServoTypes.h"
 #include "mozilla/ServoBindingTypes.h"
 #include "mozilla/ServoElementSnapshot.h"
 #include "mozilla/css/SheetParsingMode.h"
 #include "mozilla/EffectCompositor.h"
+#include "mozilla/ComputedTimingFunction.h"
 #include "nsChangeHint.h"
 #include "nsCSSPseudoClasses.h"
 #include "nsStyleStruct.h"
 
 /*
  * API for Servo to access Gecko data structures. This file must compile as valid
  * C code in order for the binding generator to parse it.
  *
@@ -188,16 +189,21 @@ void Gecko_UpdateAnimations(RawGeckoElem
                             nsIAtom* aPseudoTagOrNull,
                             ServoComputedValuesBorrowedOrNull aComputedValues,
                             ServoComputedValuesBorrowedOrNull aParentComputedValues,
                             mozilla::UpdateAnimationsTasks aTaskBits);
 bool Gecko_ElementHasAnimations(RawGeckoElementBorrowed aElement,
                                 nsIAtom* aPseudoTagOrNull);
 bool Gecko_ElementHasCSSAnimations(RawGeckoElementBorrowed aElement,
                                    nsIAtom* aPseudoTagOrNull);
+double Gecko_GetProgressFromComputedTiming(RawGeckoComputedTimingBorrowed aComputedTiming);
+double Gecko_GetPositionInSegment(
+  RawGeckoAnimationPropertySegmentBorrowed aSegment,
+  double aProgress,
+  mozilla::ComputedTimingFunction::BeforeFlag aBeforeFlag);
 
 // Atoms.
 nsIAtom* Gecko_Atomize(const char* aString, uint32_t aLength);
 void Gecko_AddRefAtom(nsIAtom* aAtom);
 void Gecko_ReleaseAtom(nsIAtom* aAtom);
 const uint16_t* Gecko_GetAtomAsUTF16(nsIAtom* aAtom, uint32_t* aLength);
 bool Gecko_AtomEqualsUTF8(nsIAtom* aAtom, const char* aString, uint32_t aLength);
 bool Gecko_AtomEqualsUTF8IgnoreCase(nsIAtom* aAtom, const char* aString, uint32_t aLength);