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

Source/core/css/CSSStyleDeclaration.h

Index: Source/core/css/CSSStyleDeclaration.h
diff --git a/Source/core/css/CSSStyleDeclaration.h b/Source/core/css/CSSStyleDeclaration.h
index 36035cee1565a9d71c86469d3b37bfcd0901634a..976e880cbcfddcbebec7fa5703ad5176250b9043 100644
--- a/Source/core/css/CSSStyleDeclaration.h
+++ b/Source/core/css/CSSStyleDeclaration.h
@@ -35,13 +35,15 @@ class CSSValue;
 class ExceptionState;
 class MutableStylePropertySet;
 
-class CSSStyleDeclaration : public ScriptWrappable {
-    WTF_MAKE_NONCOPYABLE(CSSStyleDeclaration); WTF_MAKE_FAST_ALLOCATED;
+class CSSStyleDeclaration : public NoBaseWillBeGarbageCollectedFinalized<CSSStyleDeclaration>, public ScriptWrappable {
+    WTF_MAKE_NONCOPYABLE(CSSStyleDeclaration); WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED;
 public:
     virtual ~CSSStyleDeclaration() { }
 
+#if !ENABLE(OILPAN)
     virtual void ref() = 0;
     virtual void deref() = 0;
+#endif
 
     virtual CSSRule* parentRule() const = 0;
     virtual String cssText() const = 0;
@@ -68,6 +70,8 @@ public:
     virtual bool cssPropertyMatches(CSSPropertyID, const CSSValue*) const = 0;
     virtual CSSStyleSheet* parentStyleSheet() const { return 0; }
 
+    virtual void trace(Visitor*) = 0;
+
 protected:
     CSSStyleDeclaration()
     {