Oilpan: move editing objects to the heap.

Source/core/editing/UndoStep.h

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 14 matching lines @@
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef UndoStep_h
 #define UndoStep_h
 
 #include "core/editing/EditAction.h"
+#include "platform/heap/Handle.h"
 #include "wtf/RefCounted.h"
 
 namespace WebCore {
 
 class LocalFrame;
 
-class UndoStep : public RefCounted<UndoStep> {
+class UndoStep : public RefCountedWillBeGarbageCollectedFinalized<UndoStep> {
 public:
     virtual ~UndoStep() { }
+    virtual void trace(Visitor*) { }
 
     virtual bool belongsTo(const LocalFrame&) const = 0;
     virtual void unapply() = 0;
     virtual void reapply() = 0;
     virtual EditAction editingAction() const = 0;
 };
 
 }
 
 #endif