Add additive animation support for CSS property motion-rotation

third_party/WebKit/Source/core/css/resolver/StyleBuilderConverter.cpp

Index: third_party/WebKit/Source/core/css/resolver/StyleBuilderConverter.cpp
diff --git a/third_party/WebKit/Source/core/css/resolver/StyleBuilderConverter.cpp b/third_party/WebKit/Source/core/css/resolver/StyleBuilderConverter.cpp
index b0b3a125e7762ac06e6b80bcdea6b790e6b41df5..7a5d2d612b77833fe1bd80929125b57eb1c14729 100644
--- a/third_party/WebKit/Source/core/css/resolver/StyleBuilderConverter.cpp
+++ b/third_party/WebKit/Source/core/css/resolver/StyleBuilderConverter.cpp
@@ -630,6 +630,11 @@ float StyleBuilderConverter::convertNumberOrPercentage(StyleResolverState& state
 
 StyleMotionRotation StyleBuilderConverter::convertMotionRotation(StyleResolverState&, const CSSValue& value)
 {
+    return convertMotionRotation(value);
+}
+
+StyleMotionRotation StyleBuilderConverter::convertMotionRotation(const CSSValue& value)
+{
     StyleMotionRotation result(0, MotionRotationFixed);
 
     const CSSValueList& list = toCSSValueList(value);