Web Animations CSS: Support animation of background-position and background-image

Source/core/animation/AnimatableValue.h

Index: Source/core/animation/AnimatableValue.h
diff --git a/Source/core/animation/AnimatableValue.h b/Source/core/animation/AnimatableValue.h
index adc85162ff9613e942b555f3ab15896b4a0f6264..335ae695eb7e447a1e1dc19e98d587a9578f875d 100644
--- a/Source/core/animation/AnimatableValue.h
+++ b/Source/core/animation/AnimatableValue.h
@@ -59,6 +59,7 @@ public:
     bool isLengthBox() const { return type() == TypeLengthBox; }
     bool isLengthSize() const { return type() == TypeLengthSize; }
     bool isNeutral() const { return type() == TypeNeutral; }
+    bool isRepeatable() const { return type() == TypeRepeatable; }
     bool isSVGLength() const { return type() == TypeSVGLength; }
     bool isShapeValue() const { return type() == TypeShapeValue; }
     bool isSVGPaint() const { return type() == TypeSVGPaint; }
@@ -66,6 +67,12 @@ public:
     bool isUnknown() const { return type() == TypeUnknown; }
     bool isVisibility() const { return type() == TypeVisibility; }
 
+    bool isSameType(const AnimatableValue* value) const
+    {
+        ASSERT(value);
+        return value->type() == type();
+    }
+
 protected:
     enum AnimatableType {
         TypeClipPathOperation,
@@ -76,6 +83,7 @@ protected:
         TypeLengthBox,
         TypeLengthSize,
         TypeNeutral,
+        TypeRepeatable,
         TypeSVGLength,
         TypeShapeValue,
         TypeSVGPaint,
@@ -84,12 +92,6 @@ protected:
         TypeVisibility,
     };
 
-    bool isSameType(const AnimatableValue* value) const
-    {
-        ASSERT(value);
-        return value->type() == type();
-    }
-
     virtual PassRefPtr<AnimatableValue> interpolateTo(const AnimatableValue*, double fraction) const = 0;
     static PassRefPtr<AnimatableValue> defaultInterpolateTo(const AnimatableValue* left, const AnimatableValue* right, double fraction) { return takeConstRef((fraction < 0.5) ? left : right); }