Have ScriptPromiseResolver on the Oilpan heap always.

Source/modules/webaudio/AbstractAudioContext.h

 /*
  * Copyright (C) 2010, 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 227 matching lines @@
     SecurityOrigin* securityOrigin() const;
 
 protected:
     explicit AbstractAudioContext(Document*);
     AbstractAudioContext(Document*, unsigned numberOfChannels, size_t numberOfFrames, float sampleRate);
 
     void setContextState(AudioContextState);
     virtual void didClose() {}
     void uninitialize();
 
-    RefPtrWillBeMember<ScriptPromiseResolver> m_offlineResolver;
+    Member<ScriptPromiseResolver> m_offlineResolver;
 
     // FIXME(dominicc): Move m_resumeResolvers to AudioContext, because only
     // it creates these Promises.
     // Vector of promises created by resume(). It takes time to handle them, so we collect all of
     // the promises here until they can be resolved or rejected.
-    WillBeHeapVector<RefPtrWillBeMember<ScriptPromiseResolver>> m_resumeResolvers;
+    HeapVector<Member<ScriptPromiseResolver>> m_resumeResolvers;
 private:
     void initialize();
 
     bool m_isCleared;
     void clear();
 
     void throwExceptionForClosedState(ExceptionState&);
 
     // Set to true when the destination node has been initialized and is ready to process data.
     bool m_isInitialized;
@@ skipping 50 matching lines @@
     void handleStoppableSourceNodes();
 
     // This is considering 32 is large enough for multiple channels audio.
     // It is somewhat arbitrary and could be increased if necessary.
     enum { MaxNumberOfChannels = 32 };
 };
 
 } // namespace blink
 
 #endif // AbstractAudioContext_h