Oilpan: make DataObject and SharedWorker heap Supplementables.

Source/core/clipboard/DataObject.h

Index: Source/core/clipboard/DataObject.h
diff --git a/Source/core/clipboard/DataObject.h b/Source/core/clipboard/DataObject.h
index 247ca0f5bc62444928d015ec407cf0c27f4e9a95..905ecbb22a16f2485c9358ae4d22444b86631747 100644
--- a/Source/core/clipboard/DataObject.h
+++ b/Source/core/clipboard/DataObject.h
@@ -50,7 +50,8 @@ class SharedBuffer;
 // A data object for holding data that would be in a clipboard or moved
 // during a drag-n-drop operation. This is the data that WebCore is aware
 // of and is not specific to a platform.
-class DataObject : public RefCountedWillBeGarbageCollectedFinalized<DataObject>, public Supplementable<DataObject> {
+class DataObject : public RefCountedWillBeGarbageCollectedFinalized<DataObject>, public WillBeHeapSupplementable<DataObject> {
+    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(DataObject);
 public:
     static PassRefPtrWillBeRawPtr<DataObject> createFromPasteboard(PasteMode);
     static PassRefPtrWillBeRawPtr<DataObject> create();
@@ -95,7 +96,6 @@ public:
     const String& filenameForNavigation() const { return m_filenameForNavigation; }
     void setFilenameForNavigation(const String& filename) { m_filenameForNavigation = filename; }
 
-    // FIXME: oilpan: This trace() has to trace Supplementable.
     void trace(Visitor*);
 
 private: