Have ScriptPromiseResolver on the Oilpan heap always.

Source/modules/webaudio/AbstractAudioContext.h

Index: Source/modules/webaudio/AbstractAudioContext.h
diff --git a/Source/modules/webaudio/AbstractAudioContext.h b/Source/modules/webaudio/AbstractAudioContext.h
index a809701e3d124dc7eaa80793b39b21c07a30ef3d..bf6d816fdaf82d390728af352b3b57a4b4e60664 100644
--- a/Source/modules/webaudio/AbstractAudioContext.h
+++ b/Source/modules/webaudio/AbstractAudioContext.h
@@ -245,13 +245,13 @@ protected:
     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();