Oilpan: keep ImageData on the heap by default.

Source/core/html/ImageData.h

Index: Source/core/html/ImageData.h
diff --git a/Source/core/html/ImageData.h b/Source/core/html/ImageData.h
index 84ac27a4e3a1e844bd7053ab6b920f5a2038c826..873693b593300608bcbff31aa44e7ec83839efce 100644
--- a/Source/core/html/ImageData.h
+++ b/Source/core/html/ImageData.h
@@ -34,21 +34,20 @@
 #include "core/dom/DOMTypedArray.h"
 #include "platform/geometry/IntSize.h"
 #include "platform/heap/Handle.h"
-#include "wtf/RefCounted.h"
 #include "wtf/RefPtr.h"
 
 namespace blink {
 
 class ExceptionState;
 
-class CORE_EXPORT ImageData final : public RefCountedWillBeGarbageCollectedFinalized<ImageData>, public ScriptWrappable {
+class CORE_EXPORT ImageData final : public GarbageCollectedFinalized<ImageData>, public ScriptWrappable {
     DEFINE_WRAPPERTYPEINFO();
 public:
-    static PassRefPtrWillBeRawPtr<ImageData> create(const IntSize&);
-    static PassRefPtrWillBeRawPtr<ImageData> create(const IntSize&, PassRefPtr<DOMUint8ClampedArray>);
-    static PassRefPtrWillBeRawPtr<ImageData> create(unsigned width, unsigned height, ExceptionState&);
-    static PassRefPtrWillBeRawPtr<ImageData> create(DOMUint8ClampedArray*, unsigned width, ExceptionState&);
-    static PassRefPtrWillBeRawPtr<ImageData> create(DOMUint8ClampedArray*, unsigned width, unsigned height, ExceptionState&);
+    static ImageData* create(const IntSize&);
+    static ImageData* create(const IntSize&, PassRefPtr<DOMUint8ClampedArray>);
+    static ImageData* create(unsigned width, unsigned height, ExceptionState&);
+    static ImageData* create(DOMUint8ClampedArray*, unsigned width, ExceptionState&);
+    static ImageData* create(DOMUint8ClampedArray*, unsigned width, unsigned height, ExceptionState&);
 
     IntSize size() const { return m_size; }
     int width() const { return m_size.width(); }
@@ -58,6 +57,8 @@ public:
 
     DEFINE_INLINE_TRACE() { }
 
+    void dispose();
+
     virtual v8::Local<v8::Object> associateWithWrapper(v8::Isolate*, const WrapperTypeInfo*, v8::Local<v8::Object> wrapper) override;
 
 private: