Oilpan: move custom element objects to the heap.

Source/core/dom/custom/CustomElementMicrotaskStep.h

 /*
  * Copyright (C) 2013 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:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 13 matching lines @@
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * 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 CustomElementMicrotaskStep_h
 #define CustomElementMicrotaskStep_h
 
+#include "platform/heap/Handle.h"
 #include "wtf/Noncopyable.h"
 
 namespace WebCore {
 
-class CustomElementMicrotaskStep {
+class CustomElementMicrotaskStep : public NoBaseWillBeGarbageCollectedFinalized<CustomElementMicrotaskStep> {
     WTF_MAKE_NONCOPYABLE(CustomElementMicrotaskStep);
 public:
     CustomElementMicrotaskStep() { }
     virtual ~CustomElementMicrotaskStep() { }
 
     enum Result {
         ContinueWithRemoving = 0,
         ShouldStop           = 1 << 0,
         ShouldRemain         = 1 << 1
     };
 
     virtual Result process() = 0;
     virtual bool needsProcessOrStop() const = 0;
 
+    virtual void trace(Visitor*) { }
+
 #if !defined(NDEBUG)
     virtual void show(unsigned indent) = 0;
 #endif
 };
 
 }
 
 #endif // CustomElementMicrotaskStep_h