Oilpan: Remove most WillBe types from the code base

third_party/WebKit/Source/modules/presentation/Presentation.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 Presentation_h
 #define Presentation_h
 
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "core/frame/DOMWindowProperty.h"
 #include "platform/heap/Handle.h"
 #include "platform/heap/Heap.h"
 
 namespace blink {
 
 class LocalFrame;
 class PresentationReceiver;
 class PresentationRequest;
 
 // Implements the main entry point of the Presentation API corresponding to the Presentation.idl
 // See https://w3c.github.io/presentation-api/#navigatorpresentation for details.
 //
 // TODO(Oilpan): switch to GarbageCollected<Presentation> once object is unconditionally on the Oilpan heap.
 class Presentation final
     : public GarbageCollectedFinalized<Presentation>
     , public ScriptWrappable
     , public DOMWindowProperty {
-    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(Presentation);
+    USING_GARBAGE_COLLECTED_MIXIN(Presentation);
     DEFINE_WRAPPERTYPEINFO();
 public:
     static Presentation* create(LocalFrame*);
 #if !ENABLE(OILPAN)
     ~Presentation() override = default;
 #endif
 
     DECLARE_VIRTUAL_TRACE();
 
     PresentationRequest* defaultRequest() const;
     void setDefaultRequest(PresentationRequest*);
 
     PresentationReceiver* receiver();
 
 private:
     explicit Presentation(LocalFrame*);
 
     // Default PresentationRequest used by the embedder.
     Member<PresentationRequest> m_defaultRequest;
 
     // PresentationReceiver instance. It will always be nullptr if the Blink
     // instance is not running as a presentation receiver.
     Member<PresentationReceiver> m_receiver;
 };
 
 } // namespace blink
 
 #endif // Presentation_h