Revert of Move all RefPtr's to CSSValue to oilpan transition types, except for the one in CSSCursorImageValue.

Source/core/css/CSSValueList.cpp

Index: Source/core/css/CSSValueList.cpp
diff --git a/Source/core/css/CSSValueList.cpp b/Source/core/css/CSSValueList.cpp
index b41d46560aab423ca4c00ba0417f95995da9fe7c..a229067e6dac457b50fe42b2e32235ad91d44b9b 100644
--- a/Source/core/css/CSSValueList.cpp
+++ b/Source/core/css/CSSValueList.cpp
@@ -53,7 +53,7 @@
 {
     bool found = false;
     for (size_t index = 0; index < m_values.size(); index++) {
-        RefPtrWillBeMember<CSSValue>& value = m_values.at(index);
+        RefPtr<CSSValue>& value = m_values.at(index);
         if (value && val && value->equals(*val)) {
             m_values.remove(index);
             found = true;
@@ -66,7 +66,7 @@
 bool CSSValueList::hasValue(CSSValue* val) const
 {
     for (size_t index = 0; index < m_values.size(); index++) {
-        const RefPtrWillBeMember<CSSValue>& value = m_values.at(index);
+        const RefPtr<CSSValue>& value = m_values.at(index);
         if (value && val && value->equals(*val))
             return true;
     }
@@ -135,7 +135,7 @@
     if (m_values.size() != 1)
         return false;
 
-    const RefPtrWillBeMember<CSSValue>& value = m_values[0];
+    const RefPtr<CSSValue>& value = m_values[0];
     return value && value->equals(other);
 }
 
@@ -164,7 +164,6 @@
 
 void CSSValueList::traceAfterDispatch(Visitor* visitor)
 {
-    visitor->trace(m_values);
     CSSValue::traceAfterDispatch(visitor);
 }