CSSValue Immediates: Change CSSValue to an object instead of a pointer

Source/core/css/CSSUnsetValue.h

Index: Source/core/css/CSSUnsetValue.h
diff --git a/Source/core/css/CSSUnsetValue.h b/Source/core/css/CSSUnsetValue.h
index d9be3264a37fc91a2c45862c6888d76e80f7b5fe..6262db7f6450d132c9aef1579006a7bb1832cb0e 100644
--- a/Source/core/css/CSSUnsetValue.h
+++ b/Source/core/css/CSSUnsetValue.h
@@ -10,7 +10,7 @@
 
 namespace blink {
 
-class CSSUnsetValue : public CSSValue {
+class CSSUnsetValue : public CSSValueObject {
 public:
     static PassRefPtrWillBeRawPtr<CSSUnsetValue> create()
     {
@@ -21,11 +21,11 @@ public:
 
     bool equals(const CSSUnsetValue&) const { return true; }
 
-    DEFINE_INLINE_TRACE_AFTER_DISPATCH() { CSSValue::traceAfterDispatch(visitor); }
+    DEFINE_INLINE_TRACE_AFTER_DISPATCH() { CSSValueObject::traceAfterDispatch(visitor); }
 
 private:
     CSSUnsetValue()
-        : CSSValue(UnsetClass)
+        : CSSValueObject(UnsetClass)
     {
     }
 };