Oilpan: Fix build after MIDI changes.

Source/modules/webmidi/MIDIAccess.h

 /*
  * Copyright (C) 2013 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 84 matching lines @@
         Resolved,
         Stopped,
     };
 
     MIDIAccess(const MIDIOptions&, ExecutionContext*);
     ScriptPromise startRequest();
 
     void permissionDenied();
 
     void resolve();
-    void reject(PassRefPtr<DOMError>);
+    void reject(PassRefPtrWillBeRawPtr<DOMError>);
     void resolveNow();
     void rejectNow();
     // Called when the promise is resolved or rejected.
     void doPostAction(State);
 
     State m_state;
     WeakPtrFactory<MIDIAccess> m_weakPtrFactory;
     MIDIInputVector m_inputs;
     MIDIOutputVector m_outputs;
     OwnPtr<MIDIAccessor> m_accessor;
     OwnPtr<MIDIAccessResolver> m_resolver;
     MIDIOptions m_options;
     bool m_sysExEnabled;
     AsyncMethodRunner<MIDIAccess> m_asyncResolveRunner;
     AsyncMethodRunner<MIDIAccess> m_asyncRejectRunner;
-    RefPtr<DOMError> m_error;
+    RefPtrWillBeMember<DOMError> m_error;
 };
 
 } // namespace WebCore
 
 #endif // MIDIAccess_h