Move most of the [Pass]RefPtr's of CSSPrimitiveValue to our transition types.

Source/core/css/CSSBorderImageSliceValue.cpp

Index: Source/core/css/CSSBorderImageSliceValue.cpp
diff --git a/Source/core/css/CSSBorderImageSliceValue.cpp b/Source/core/css/CSSBorderImageSliceValue.cpp
index 12715bd0103961c41a8370c467b08273ce70eb60..34400a81137720cd8d20096afc00af15b51f1092 100644
--- a/Source/core/css/CSSBorderImageSliceValue.cpp
+++ b/Source/core/css/CSSBorderImageSliceValue.cpp
@@ -30,7 +30,7 @@
 
 namespace WebCore {
 
-CSSBorderImageSliceValue::CSSBorderImageSliceValue(PassRefPtr<CSSPrimitiveValue> slices, bool fill)
+CSSBorderImageSliceValue::CSSBorderImageSliceValue(PassRefPtrWillBeRawPtr<CSSPrimitiveValue> slices, bool fill)
     : CSSValue(BorderImageSliceClass)
     , m_slices(slices)
     , m_fill(fill)
@@ -55,6 +55,7 @@ bool CSSBorderImageSliceValue::equals(const CSSBorderImageSliceValue& other) con
 
 void CSSBorderImageSliceValue::traceAfterDispatch(Visitor* visitor)
 {
+    visitor->trace(m_slices);
     CSSValue::traceAfterDispatch(visitor);
 }