Oilpan: tidy up prefinalizer declarations and a registration.

Source/modules/webmidi/MIDIAccessInitializer.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MIDIAccessInitializer_h
 #define MIDIAccessInitializer_h
 
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "modules/webmidi/MIDIAccessor.h"
 #include "modules/webmidi/MIDIAccessorClient.h"
 #include "modules/webmidi/MIDIPort.h"
 #include "wtf/OwnPtr.h"
 #include "wtf/Vector.h"
 
 namespace blink {
 
 class MIDIOptions;
 class ScriptState;
 
 class MIDIAccessInitializer : public ScriptPromiseResolver, public MIDIAccessorClient {
-#if ENABLE(OILPAN)
-    USING_PRE_FINALIZER(MIDIAccessInitializer, dispose);
-#endif
+    WILL_BE_USING_PRE_FINALIZER(MIDIAccessInitializer, dispose);
 public:
     struct PortDescriptor {
         String id;
         String manufacturer;
         String name;
         MIDIPort::MIDIPortTypeCode type;
         String version;
         bool isActive;
 
         PortDescriptor(const String& id, const String& manufacturer, const String& name, MIDIPort::MIDIPortTypeCode type, const String& version, bool isActive)
@@ skipping 33 matching lines @@
     ScriptPromise start();
     void dispose();
 
     OwnPtr<MIDIAccessor> m_accessor;
     Vector<PortDescriptor> m_portDescriptors;
     bool m_requestSysex;
 };
 
 } // namespace blink
 
-
 #endif // MIDIAccessInitializer_h