Oilpan: Remove most WillBe types from the code base

third_party/WebKit/Source/modules/mediasource/MediaSource.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 35 matching lines @@
 class ExceptionState;
 class GenericEventQueue;
 class WebSourceBuffer;
 
 class MediaSource final
     : public RefCountedGarbageCollectedEventTargetWithInlineData<MediaSource>
     , public HTMLMediaSource
     , public ActiveDOMObject {
     REFCOUNTED_GARBAGE_COLLECTED_EVENT_TARGET(MediaSource);
     DEFINE_WRAPPERTYPEINFO();
-    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(MediaSource);
+    USING_GARBAGE_COLLECTED_MIXIN(MediaSource);
 public:
     static const AtomicString& openKeyword();
     static const AtomicString& closedKeyword();
     static const AtomicString& endedKeyword();
 
     static MediaSource* create(ExecutionContext*);
     ~MediaSource() override;
 
     static void logAndThrowDOMException(ExceptionState&, const ExceptionCode& error, const String& message);
 
@@ skipping 55 matching lines @@
     PassOwnPtr<WebSourceBuffer> createWebSourceBuffer(const String& type, const String& codecs, ExceptionState&);
     void scheduleEvent(const AtomicString& eventName);
     void endOfStreamInternal(const WebMediaSource::EndOfStreamStatus, ExceptionState&);
 
     // Implements the duration change algorithm.
     // https://dvcs.w3.org/hg/html-media/raw-file/default/media-source/media-source.html#duration-change-algorithm
     void durationChangeAlgorithm(double newDuration);
 
     OwnPtr<WebMediaSource> m_webMediaSource;
     AtomicString m_readyState;
-    OwnPtrWillBeMember<GenericEventQueue> m_asyncEventQueue;
-    RawPtrWillBeWeakMember<HTMLMediaElement> m_attachedElement;
+    Member<GenericEventQueue> m_asyncEventQueue;
+    WeakMember<HTMLMediaElement> m_attachedElement;
 
     Member<SourceBufferList> m_sourceBuffers;
     Member<SourceBufferList> m_activeSourceBuffers;
 
     bool m_isAddedToRegistry;
 };
 
 } // namespace blink
 
 #endif // MediaSource_h