Oilpan: Prepare to move ImageLoader and its subclasses to Oilpan heap.

Source/core/html/HTMLVideoElement.h

 /*
  * Copyright (C) 2007, 2008, 2009, 2010 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 23 matching lines @@
 }
 
 namespace WebCore {
 
 class ExceptionState;
 class HTMLImageLoader;
 
 class HTMLVideoElement FINAL : public HTMLMediaElement, public CanvasImageSource {
 public:
     static PassRefPtrWillBeRawPtr<HTMLVideoElement> create(Document&);
+    virtual void trace(Visitor*) OVERRIDE;
 
     unsigned videoWidth() const;
     unsigned videoHeight() const;
 
     // Fullscreen
     void webkitEnterFullscreen(ExceptionState&);
     void webkitExitFullscreen();
     bool webkitSupportsFullscreen();
     bool webkitDisplayingFullscreen();
 
@@ skipping 34 matching lines @@
     virtual bool hasVideo() const OVERRIDE { return webMediaPlayer() && webMediaPlayer()->hasVideo(); }
     bool supportsFullscreen() const;
     virtual bool isURLAttribute(const Attribute&) const OVERRIDE;
     virtual const AtomicString imageSourceURL() const OVERRIDE;
 
     bool hasAvailableVideoFrame() const;
     virtual void updateDisplayState() OVERRIDE;
     virtual void didMoveToNewDocument(Document& oldDocument) OVERRIDE;
     virtual void setDisplayMode(DisplayMode) OVERRIDE;
 
-    OwnPtr<HTMLImageLoader> m_imageLoader;
+    OwnPtrWillBeMember<HTMLImageLoader> m_imageLoader;
 
     AtomicString m_defaultPosterURL;
 };
 
 } //namespace
 
 #endif