Oilpan: fix build after r201436, r201444.

Source/core/inspector/LayoutEditor.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef LayoutEditor_h
 #define LayoutEditor_h
 
 #include "core/CSSPropertyNames.h"
 #include "core/CoreExport.h"
 #include "core/css/CSSPrimitiveValue.h"
 #include "core/dom/Node.h"
 #include "platform/heap/Handle.h"
 #include "wtf/PassOwnPtr.h"
 #include "wtf/RefPtr.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
 class CSSPrimitiveValue;
 class InspectorCSSAgent;
 class JSONArray;
 class JSONObject;
 
-class CORE_EXPORT LayoutEditor final: public NoBaseWillBeGarbageCollectedFinalized<LayoutEditor> {
-    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(LayoutEditor);
+class CORE_EXPORT LayoutEditor final : public NoBaseWillBeGarbageCollectedFinalized<LayoutEditor> {
 public:
     static PassOwnPtrWillBeRawPtr<LayoutEditor> create(InspectorCSSAgent* cssAgent)
     {
         return adoptPtrWillBeNoop(new LayoutEditor(cssAgent));
     }
 
     void setNode(Node*);
     PassRefPtr<JSONObject> buildJSONInfo() const;
     void overlayStartedPropertyChange(const String&);
     void overlayPropertyChanged(float);
     void overlayEndedPropertyChange();
 
-    DECLARE_VIRTUAL_TRACE();
+    DECLARE_TRACE();
 
 private:
     explicit LayoutEditor(InspectorCSSAgent*);
     RefPtrWillBeRawPtr<CSSPrimitiveValue> getPropertyCSSValue(CSSPropertyID) const;
     PassRefPtr<JSONObject> createValueDescription(const String&) const;
     void appendAnchorFor(JSONArray*, const String&, const String&, const FloatPoint&, const FloatPoint&) const;
 
     RefPtrWillBeMember<Element> m_element;
     RawPtrWillBeMember<InspectorCSSAgent> m_cssAgent;
     CSSPropertyID m_changingProperty;
     float m_propertyInitialValue;
     float m_factor;
     CSSPrimitiveValue::UnitType m_valueUnitType;
 };
 
 } // namespace blink
 
 
 #endif // !defined(LayoutEditor_h)