Oilpan: Move CSSStyleDeclaration and subclasses to the heap using transistion types.

Source/core/css/CSSComputedStyleDeclaration.h

Index: Source/core/css/CSSComputedStyleDeclaration.h
diff --git a/Source/core/css/CSSComputedStyleDeclaration.h b/Source/core/css/CSSComputedStyleDeclaration.h
index 5c9dc095bee70f98966405e9106c2c856ecb1c38..780e89abc76ec792a5d714bf0eb921044b7bc444 100644
--- a/Source/core/css/CSSComputedStyleDeclaration.h
+++ b/Source/core/css/CSSComputedStyleDeclaration.h
@@ -49,14 +49,16 @@ enum EUpdateLayout { DoNotUpdateLayout = false, UpdateLayout = true };
 
 class CSSComputedStyleDeclaration FINAL : public CSSStyleDeclaration {
 public:
-    static PassRefPtr<CSSComputedStyleDeclaration> create(PassRefPtr<Node> node, bool allowVisitedStyle = false, const String& pseudoElementName = String())
+    static PassRefPtrWillBeRawPtr<CSSComputedStyleDeclaration> create(PassRefPtr<Node> node, bool allowVisitedStyle = false, const String& pseudoElementName = String())
     {
-        return adoptRef(new CSSComputedStyleDeclaration(node, allowVisitedStyle, pseudoElementName));
+        return adoptRefWillBeNoop(new CSSComputedStyleDeclaration(node, allowVisitedStyle, pseudoElementName));
     }
     virtual ~CSSComputedStyleDeclaration();
 
+#if !ENABLE(OILPAN)
     virtual void ref() OVERRIDE;
     virtual void deref() OVERRIDE;
+#endif
 
     PassRefPtrWillBeRawPtr<CSSValue> getPropertyCSSValue(CSSPropertyID) const;
     String getPropertyValue(CSSPropertyID) const;
@@ -71,6 +73,8 @@ public:
 
     PassRefPtrWillBeRawPtr<MutableStylePropertySet> copyPropertiesInSet(const Vector<CSSPropertyID>&) const;
 
+    virtual void trace(Visitor* visitor) { }
+
 private:
     CSSComputedStyleDeclaration(PassRefPtr<Node>, bool allowVisitedStyle, const String&);