Web Animations API: Deferred computation of interpolated values

Source/core/animation/StringKeyframe.h

Index: Source/core/animation/StringKeyframe.h
diff --git a/Source/core/animation/StringKeyframe.h b/Source/core/animation/StringKeyframe.h
index 7bf226e8cc74d0d20c977675bf70a7667169d84d..ed7c75906e8a7c45fcf490192ccef7f0a5b9caee 100644
--- a/Source/core/animation/StringKeyframe.h
+++ b/Source/core/animation/StringKeyframe.h
@@ -35,10 +35,7 @@ public:
         PropertySpecificKeyframe(double offset, PassRefPtr<TimingFunction> easing, CSSValue*, AnimationEffect::CompositeOperation);
 
         CSSValue* value() const { return m_value.get(); }
-        virtual const PassRefPtrWillBeRawPtr<AnimatableValue> getAnimatableValue() const OVERRIDE FINAL {
-            ASSERT(m_animatableValueCache);
-            return m_animatableValueCache.get();
-        }
+        virtual const PassRefPtrWillBeRawPtr<AnimatableValue> getAnimatableValue() const OVERRIDE FINAL { return m_animatableValueCache; }
 
         virtual PassOwnPtrWillBeRawPtr<Keyframe::PropertySpecificKeyframe> neutralKeyframe(double offset, PassRefPtr<TimingFunction> easing) const OVERRIDE FINAL;
         virtual PassRefPtrWillBeRawPtr<Interpolation> createInterpolation(CSSPropertyID, WebCore::Keyframe::PropertySpecificKeyframe* end, Element*) const OVERRIDE FINAL;