Web Animations API: Reuse cached InterpolableValue during interpolation

Source/core/animation/InterpolableValue.cpp

Index: Source/core/animation/InterpolableValue.cpp
diff --git a/Source/core/animation/InterpolableValue.cpp b/Source/core/animation/InterpolableValue.cpp
index 67bcfb8aa68320cd7388f64b4fff11ce474abfe9..ed84e275a5f2e89e129256a2eed5f202252404a4 100644
--- a/Source/core/animation/InterpolableValue.cpp
+++ b/Source/core/animation/InterpolableValue.cpp
@@ -4,48 +4,43 @@
 
 #include "config.h"
 #include "core/animation/InterpolableValue.h"
+#include "platform/animation/AnimationUtilities.h"
 
 namespace blink {
 
 DEFINE_EMPTY_DESTRUCTOR_WILL_BE_REMOVED(InterpolableValue);
 
-PassOwnPtrWillBeRawPtr<InterpolableValue> InterpolableNumber::interpolate(const InterpolableValue &to, const double progress) const
+void InterpolableNumber::assignInterpolation(const InterpolableValue& from, const InterpolableValue& to, const double progress)
 {
+    const InterpolableNumber& fromNumber = toInterpolableNumber(from);
     const InterpolableNumber& toNumber = toInterpolableNumber(to);
-    if (!progress)
-        return create(m_value);
-    if (progress == 1)
-        return create(toNumber.m_value);
-    return create(m_value * (1 - progress) + toNumber.m_value * progress);
+    if (progress == 0)
+        m_value = fromNumber.m_value;
+    else if (progress == 1)
+        m_value = toNumber.m_value;
+    else
+        m_value = blend(fromNumber.m_value, toNumber.m_value, progress);
 }
 
-PassOwnPtrWillBeRawPtr<InterpolableValue> InterpolableBool::interpolate(const InterpolableValue &to, const double progress) const
+void InterpolableBool::assignInterpolation(const InterpolableValue& from, const InterpolableValue& to, const double progress)
 {
-    if (progress < 0.5) {
-        return clone();
-    }
-    return to.clone();
+    const InterpolableBool& fromBool = toInterpolableBool(from);
+    const InterpolableBool& toBool = toInterpolableBool(to);
+    if (progress < 0.5)
+        m_value = fromBool.m_value;
+    else
+        m_value = toBool.m_value;
 }
 
-PassOwnPtrWillBeRawPtr<InterpolableValue> InterpolableList::interpolate(const InterpolableValue &to, const double progress) const
+void InterpolableList::assignInterpolation(const InterpolableValue& from, const InterpolableValue& to, const double progress)
 {
+    const InterpolableList& fromList = toInterpolableList(from);
     const InterpolableList& toList = toInterpolableList(to);
+    ASSERT(fromList.m_size == m_size);
     ASSERT(toList.m_size == m_size);
 
-    if (!progress) {
-        return create(*this);
-    }
-    if (progress == 1) {
-        return InterpolableList::create(toList);
-    }
-
-    OwnPtrWillBeRawPtr<InterpolableList> result = create(m_size);
-    for (size_t i = 0; i < m_size; i++) {
-        ASSERT(m_values[i]);
-        ASSERT(toList.m_values[i]);
-        result->set(i, m_values[i]->interpolate(*(toList.m_values[i]), progress));
-    }
-    return result.release();
+    for (size_t i = 0; i < m_size; ++i)
+        m_values.at(i)->assignInterpolation(*fromList.m_values.at(i), *toList.m_values.at(i), progress);
 }
 
 void InterpolableList::trace(Visitor* visitor)
@@ -56,14 +51,16 @@ void InterpolableList::trace(Visitor* visitor)
     InterpolableValue::trace(visitor);
 }
 
-PassOwnPtrWillBeRawPtr<InterpolableValue> InterpolableAnimatableValue::interpolate(const InterpolableValue &other, const double percentage) const
+void InterpolableAnimatableValue::assignInterpolation(const InterpolableValue& from, const InterpolableValue& to, const double progress)
 {
-    const InterpolableAnimatableValue& otherValue = toInterpolableAnimatableValue(other);
-    if (!percentage)
-        return create(m_value);
-    if (percentage == 1)
-        return create(otherValue.m_value);
-    return create(AnimatableValue::interpolate(m_value.get(), otherValue.m_value.get(), percentage));
+    const InterpolableAnimatableValue& fromValue = toInterpolableAnimatableValue(from);
+    const InterpolableAnimatableValue& toValue = toInterpolableAnimatableValue(to);
+    if (progress == 0)
+        m_value = fromValue.m_value;
+    else if (progress == 1)
+        m_value = toValue.m_value;
+    else
+        m_value = AnimatableValue::interpolate(fromValue.m_value.get(), toValue.m_value.get(), progress);
 }
 
 void InterpolableAnimatableValue::trace(Visitor* visitor)