Add additive animation support for border-radius CSS properties

third_party/WebKit/Source/core/animation/CSSLengthPairInterpolationType.h

Index: third_party/WebKit/Source/core/animation/CSSLengthPairInterpolationType.h
diff --git a/third_party/WebKit/Source/core/animation/CSSPositionInterpolationType.h b/third_party/WebKit/Source/core/animation/CSSLengthPairInterpolationType.h
similarity index 61%
copy from third_party/WebKit/Source/core/animation/CSSPositionInterpolationType.h
copy to third_party/WebKit/Source/core/animation/CSSLengthPairInterpolationType.h
index 523542e0b575ea3fae5693fa19166742c32261a0..750f9510792ccc717cbf5445ac999c22cc848362 100644
--- a/third_party/WebKit/Source/core/animation/CSSPositionInterpolationType.h
+++ b/third_party/WebKit/Source/core/animation/CSSLengthPairInterpolationType.h
@@ -2,20 +2,19 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CSSPositionInterpolationType_h
-#define CSSPositionInterpolationType_h
+#ifndef CSSLengthPairInterpolationType_h
+#define CSSLengthPairInterpolationType_h
 
+#include "core/animation/CSSLengthInterpolationType.h"
 #include "core/animation/CSSLengthListInterpolationType.h"
-
-#include "core/animation/CSSPositionAxisListInterpolationType.h"
 #include "core/animation/ListInterpolationFunctions.h"
 #include "core/css/CSSValuePair.h"
 
 namespace blink {
 
-class CSSPositionInterpolationType : public CSSLengthListInterpolationType {
+class CSSLengthPairInterpolationType : public CSSLengthListInterpolationType {
 public:
-    CSSPositionInterpolationType(CSSPropertyID property)
+    CSSLengthPairInterpolationType(CSSPropertyID property)
         : CSSLengthListInterpolationType(property)
     { }
 
@@ -24,11 +23,11 @@ private:
     {
         const CSSValuePair& pair = toCSSValuePair(value);
         return ListInterpolationFunctions::createList(2, [&pair](size_t index) {
-            return CSSPositionAxisListInterpolationType::convertPositionAxisCSSValue(index == 0 ? pair.first() : pair.second());
+            return CSSLengthInterpolationType::maybeConvertCSSValue(index == 0 ? pair.first() : pair.second());
         });
     }
 };
 
 } // namespace blink
 
-#endif // CSSPositionInterpolationType_h
+#endif // CSSLengthPairInterpolationType_h