Animation: Add template for ListStyleInterpolation

Source/core/animation/LengthStyleInterpolation.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef LengthStyleInterpolation_h
 #define LengthStyleInterpolation_h
 
 #include "core/animation/StyleInterpolation.h"
 #include "core/css/CSSPrimitiveValue.h"
 #include "platform/Length.h"
 
 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));
     }
 
     static bool canCreateFrom(const CSSValue&);
 
     virtual void apply(StyleResolverState&) const override;
 
     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;
 };
 
 }
 
 #endif