Oilpan: fix build after r192098.

Source/core/inspector/InspectorOverlay.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:
  *
  * 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 20 matching lines @@
 
 #include "core/inspector/InspectorHighlight.h"
 #include "platform/geometry/FloatQuad.h"
 #include "platform/heap/Handle.h"
 #include "wtf/Forward.h"
 
 namespace blink {
 
 struct InspectorHighlightConfig;
 
-class InspectorOverlay : public NoBaseWillBeGarbageCollectedFinalized<InspectorOverlay> {
+class InspectorOverlay : public WillBeGarbageCollectedMixin {
 public:
     virtual ~InspectorOverlay() { }
 
     virtual void update() = 0;
     virtual void setPausedInDebuggerMessage(const String*) = 0;
     virtual void setInspectModeEnabled(bool) = 0;
     virtual void hideHighlight() = 0;
     virtual void highlightNode(Node*, Node* eventTarget, const InspectorHighlightConfig&, bool omitTooltip) = 0;
     virtual void highlightQuad(PassOwnPtr<FloatQuad>, const InspectorHighlightConfig&) = 0;
     virtual void showAndHideViewSize(bool showGrid) = 0;
     virtual void suspendUpdates() = 0;
     virtual void resumeUpdates() = 0;
 
+    DEFINE_INLINE_VIRTUAL_TRACE() { }
+
     class Listener : public WillBeGarbageCollectedMixin {
     public:
         virtual ~Listener() { }
         virtual void overlayResumed() = 0;
         virtual void overlaySteppedOver() = 0;
     };
     virtual void setListener(Listener*) = 0;
 };
 
 } // namespace blink
 
 
 #endif // InspectorOverlay_h