Animation: Add template for ListStyleInterpolation

Source/core/animation/LengthStyleInterpolation.h

Index: Source/core/animation/LengthStyleInterpolation.h
diff --git a/Source/core/animation/LengthStyleInterpolation.h b/Source/core/animation/LengthStyleInterpolation.h
index cd8ab4cd89f4b812b33acf9dcfe442d295e52387..0b5ad23a2bfe9190ac0a34a89e37f46ca6d094a1 100644
--- a/Source/core/animation/LengthStyleInterpolation.h
+++ b/Source/core/animation/LengthStyleInterpolation.h
@@ -13,6 +13,9 @@ namespace blink {
 
 class LengthStyleInterpolation : public StyleInterpolation {
 public:
+
+    typedef void NonInterpolableType;
+
     static PassRefPtrWillBeRawPtr<LengthStyleInterpolation> create(const CSSValue& start, const CSSValue& end, CSSPropertyID id, InterpolationRange range)
     {
         return adoptRefWillBeNoop(new LengthStyleInterpolation(lengthToInterpolableValue(start), lengthToInterpolableValue(end), id, range));
@@ -24,22 +27,26 @@ public:
 
     virtual void trace(Visitor*) override;
 
+    static PassOwnPtrWillBeRawPtr<InterpolableValue> toInterpolableValue(const CSSValue&);
+    static PassRefPtrWillBeRawPtr<CSSPrimitiveValue> fromInterpolableValue(const InterpolableValue&, InterpolationRange);
+
+    static PassOwnPtrWillBeRawPtr<InterpolableValue> lengthToInterpolableValue(const CSSValue& value)
+    {
+        return toInterpolableValue(value);
+    }
+
+    static PassRefPtrWillBeRawPtr<CSSPrimitiveValue> interpolableValueToLength(const InterpolableValue& value, InterpolationRange range)
+    {
+        return fromInterpolableValue(value, range);
+    }
+

[samli, 2015/01/23 03:23:36]

Don't think there is any value to having lengthToIntepolableValue() or
interpolableValueToLength(). Seems like these are just aliases but don't really
add any value since they are static and are hence called like
LengthStyleInterpolation::toInterpolableValue() which is clear enough.

[evemj (not active), 2015/01/28 00:41:13]

Done.

 private:
     LengthStyleInterpolation(PassOwnPtrWillBeRawPtr<InterpolableValue> start, PassOwnPtrWillBeRawPtr<InterpolableValue> end, CSSPropertyID id,  InterpolationRange range)
         : StyleInterpolation(start, end, id)
         , m_range(range)
         { }
 
-    static PassOwnPtrWillBeRawPtr<InterpolableValue> lengthToInterpolableValue(const CSSValue&);
-    static PassRefPtrWillBeRawPtr<CSSPrimitiveValue> interpolableValueToLength(const InterpolableValue*, InterpolationRange);
-
     InterpolationRange m_range;
-
-    friend class AnimationLengthStyleInterpolationTest;
-    friend class LengthBoxStyleInterpolation;
-    friend class ShadowStyleInterpolation;
-    friend class LengthPairStyleInterpolation;
-    friend class LengthPoint3DStyleInterpolation;
 };
 
 }