Revert of Add additive animation support for CSS property background-position

third_party/WebKit/Source/core/animation/CSSLengthListInterpolationType.cpp

Index: third_party/WebKit/Source/core/animation/CSSLengthListInterpolationType.cpp
diff --git a/third_party/WebKit/Source/core/animation/CSSLengthListInterpolationType.cpp b/third_party/WebKit/Source/core/animation/CSSLengthListInterpolationType.cpp
index a99f580c3ff366fe1958fa1b11c4990cf4b728f0..f70a66c1f08e7d63de69de62c239cdbc480bac24 100644
--- a/third_party/WebKit/Source/core/animation/CSSLengthListInterpolationType.cpp
+++ b/third_party/WebKit/Source/core/animation/CSSLengthListInterpolationType.cpp
@@ -33,43 +33,48 @@
     });
 }
 
-static InterpolationValue maybeConvertLengthList(const Vector<Length>& lengthList, float zoom)
-{
-    if (lengthList.isEmpty())
-        return nullptr;
-
-    return ListInterpolationFunctions::createList(lengthList.size(), [&lengthList, zoom](size_t index) {
-        return CSSLengthInterpolationType::maybeConvertLength(lengthList[index], zoom);
-    });
-}
-
 InterpolationValue CSSLengthListInterpolationType::maybeConvertInitial() const
 {
     return maybeConvertLengthList(LengthListPropertyFunctions::getInitialLengthList(cssProperty()), 1);
+}
+
+InterpolationValue CSSLengthListInterpolationType::maybeConvertLengthList(const RefVector<Length>* lengthList, float zoom) const
+{
+    if (!lengthList || lengthList->size() == 0)
+        return nullptr;
+
+    return ListInterpolationFunctions::createList(lengthList->size(), [lengthList, zoom](size_t index) {
+        return CSSLengthInterpolationType::maybeConvertLength(lengthList->at(index), zoom);
+    });
 }
 
 class ParentLengthListChecker : public InterpolationType::ConversionChecker {
 public:
     ~ParentLengthListChecker() final {}
 
-    static PassOwnPtr<ParentLengthListChecker> create(CSSPropertyID property, const Vector<Length>& inheritedLengthList)
+    static PassOwnPtr<ParentLengthListChecker> create(CSSPropertyID property, PassRefPtr<RefVector<Length>> inheritedLengthList)
     {
         return adoptPtr(new ParentLengthListChecker(property, inheritedLengthList));
     }
 
 private:
-    ParentLengthListChecker(CSSPropertyID property, const Vector<Length>& inheritedLengthList)
+    ParentLengthListChecker(CSSPropertyID property, PassRefPtr<RefVector<Length>> inheritedLengthList)
         : m_property(property)
         , m_inheritedLengthList(inheritedLengthList)
     { }
 
     bool isValid(const InterpolationEnvironment& environment, const InterpolationValue& underlying) const final
     {
-        return m_inheritedLengthList == LengthListPropertyFunctions::getLengthList(m_property, *environment.state().parentStyle());
+        const RefVector<Length>* lengthList = LengthListPropertyFunctions::getLengthList(m_property, *environment.state().parentStyle());
+        if (!lengthList && !m_inheritedLengthList)
+            return true;
+        if (!lengthList || !m_inheritedLengthList)
+            return false;
+        return *m_inheritedLengthList == *lengthList;
     }
 
     CSSPropertyID m_property;
-    Vector<Length> m_inheritedLengthList;
+    RefPtr<RefVector<Length>> m_inheritedLengthList;
 };
 
 InterpolationValue CSSLengthListInterpolationType::maybeConvertInherit(const StyleResolverState& state, ConversionCheckers& conversionCheckers) const
@@ -77,8 +82,9 @@
     if (!state.parentStyle())
         return nullptr;
 
-    Vector<Length> inheritedLengthList = LengthListPropertyFunctions::getLengthList(cssProperty(), *state.parentStyle());
-    conversionCheckers.append(ParentLengthListChecker::create(cssProperty(), inheritedLengthList));
+    const RefVector<Length>* inheritedLengthList = LengthListPropertyFunctions::getLengthList(cssProperty(), *state.parentStyle());
+    conversionCheckers.append(ParentLengthListChecker::create(cssProperty(),
+        const_cast<RefVector<Length>*>(inheritedLengthList))); // Take ref.
     return maybeConvertLengthList(inheritedLengthList, state.parentStyle()->effectiveZoom());
 }
 
@@ -100,7 +106,7 @@
 
 InterpolationValue CSSLengthListInterpolationType::maybeConvertUnderlyingValue(const InterpolationEnvironment& environment) const
 {
-    Vector<Length> underlyingLengthList = LengthListPropertyFunctions::getLengthList(cssProperty(), *environment.state().style());
+    const RefVector<Length>* underlyingLengthList = LengthListPropertyFunctions::getLengthList(cssProperty(), *environment.state().style());
     return maybeConvertLengthList(underlyingLengthList, environment.state().style()->effectiveZoom());
 }
 
@@ -118,15 +124,15 @@
     ASSERT(length > 0);
     const NonInterpolableList& nonInterpolableList = toNonInterpolableList(*nonInterpolableValue);
     ASSERT(nonInterpolableList.length() == length);
-    Vector<Length> result(length);
+    RefPtr<RefVector<Length>> result = RefVector<Length>::create();
     for (size_t i = 0; i < length; i++) {
-        result[i] = (CSSLengthInterpolationType::resolveInterpolableLength(
+        result->append(CSSLengthInterpolationType::resolveInterpolableLength(
             *interpolableList.get(i),
             nonInterpolableList.get(i),
             environment.state().cssToLengthConversionData(),
             m_valueRange));
     }
-    LengthListPropertyFunctions::setLengthList(cssProperty(), *environment.state().style(), std::move(result));
+    LengthListPropertyFunctions::setLengthList(cssProperty(), *environment.state().style(), result.release());
 }
 
 } // namespace blink