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

Source/core/css/StylePropertySerializer.h

Index: Source/core/css/StylePropertySerializer.h
diff --git a/Source/core/css/StylePropertySerializer.h b/Source/core/css/StylePropertySerializer.h
index 7743d69f664e74f3fbafde9760ef7a22d8ac8205..310e1b4aec0ac6e0e1f9c457f65732f122ae00ff 100644
--- a/Source/core/css/StylePropertySerializer.h
+++ b/Source/core/css/StylePropertySerializer.h
@@ -65,22 +65,25 @@ private:
             , m_isImplicit(property.isImplicit())
             , m_isInherited(property.isInherited()) { }
 
-        PropertyValueForSerializer(CSSPropertyID id, const CSSValue* value, bool isImportant)
+        PropertyValueForSerializer(CSSPropertyID id, const CSSValue value, bool isImportant)
             : m_value(value)
             , m_id(id)
             , m_isImportant(isImportant)
-            , m_isImplicit(value->isImplicitInitialValue())
-            , m_isInherited(value->isInheritedValue()) { }
+            , m_isImplicit(value.isImplicitInitialValue())
+            , m_isInherited(value.isInheritedValue()) { }
 
         CSSPropertyID id() const { return m_id; }
-        const CSSValue* value() const { return m_value; }
+        const CSSValue value() const { return m_value; }
         bool isImportant() const { return m_isImportant; }
         bool isImplicit() const { return m_isImplicit; }
         bool isInherited() const { return m_isInherited; }
-        bool isValid() const { return m_value; }
 
+        DEFINE_INLINE_TRACE()
+        {
+            visitor->trace(m_value);
+        }
     private:
-        const CSSValue* m_value;
+        const CSSValue m_value;
         CSSPropertyID m_id;
         bool m_isImportant;
         bool m_isImplicit;
@@ -95,7 +98,7 @@ private:
         PropertyValueForSerializer propertyAt(unsigned index) const;
         bool shouldProcessPropertyAt(unsigned index) const;
         int findPropertyIndex(CSSPropertyID) const;
-        const CSSValue* getPropertyCSSValue(CSSPropertyID) const;
+        const NullableCSSValue getPropertyCSSValue(CSSPropertyID) const;
         String getPropertyValue(CSSPropertyID) const;
         bool isPropertyImplicit(CSSPropertyID) const;
         bool propertyIsImportant(CSSPropertyID) const;