Oilpan: Replace most of RefPtrs for Event objects with oilpan's transition types

Source/modules/indexeddb/IDBDatabase.h

Index: Source/modules/indexeddb/IDBDatabase.h
diff --git a/Source/modules/indexeddb/IDBDatabase.h b/Source/modules/indexeddb/IDBDatabase.h
index b771e569ef99a6caa02289873786f1b900a223f8..50c5d5f3373639759dc34d5688ae2dbd4743e2fc 100644
--- a/Source/modules/indexeddb/IDBDatabase.h
+++ b/Source/modules/indexeddb/IDBDatabase.h
@@ -98,10 +98,10 @@ public:
     bool isClosePending() const { return m_closePending; }
     void forceClose();
     const IDBDatabaseMetadata& metadata() const { return m_metadata; }
-    void enqueueEvent(PassRefPtr<Event>);
+    void enqueueEvent(PassRefPtrWillBeRawPtr<Event>);
 
     using EventTarget::dispatchEvent;
-    virtual bool dispatchEvent(PassRefPtr<Event>) OVERRIDE;
+    virtual bool dispatchEvent(PassRefPtrWillBeRawPtr<Event>) OVERRIDE;
 
     int64_t findObjectStoreId(const String& name) const;
     bool containsObjectStore(const String& name) const
@@ -144,7 +144,7 @@ private:
 
     // Keep track of the versionchange events waiting to be fired on this
     // database so that we can cancel them if the database closes.
-    Vector<RefPtr<Event> > m_enqueuedEvents;
+    WillBePersistentHeapVector<RefPtrWillBeMember<Event> > m_enqueuedEvents;
 
     RefPtr<IDBDatabaseCallbacks> m_databaseCallbacks;
 };