Make Resource RefCountedWillBeGarbageCollectedFinalized, attempt #2

third_party/WebKit/Source/core/layout/LayoutImageResourceStyleImage.cpp

 /*
  * Copyright (C) 1999 Lars Knoll <knoll@kde.org>
  * Copyright (C) 1999 Antti Koivisto <koivisto@kde.org>
  * Copyright (C) 2000 Dirk Mueller <mueller@kde.org>
  * Copyright (C) 2006 Allan Sandfeld Jensen <kde@carewolf.com>
  * Copyright (C) 2006 Samuel Weinig <sam.weinig@gmail.com>
  * Copyright (C) 2003, 2004, 2005, 2006, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2010 Patrick Gansterer <paroga@paroga.com>
  *
@@ skipping 23 matching lines @@
 namespace blink {
 
 LayoutImageResourceStyleImage::LayoutImageResourceStyleImage(StyleImage* styleImage)
     : m_styleImage(styleImage)
 {
     ASSERT(m_styleImage);
 }
 
 LayoutImageResourceStyleImage::~LayoutImageResourceStyleImage()
 {
+    ASSERT(!m_cachedImage);
 }
 
 void LayoutImageResourceStyleImage::initialize(LayoutObject* layoutObject)
 {
     LayoutImageResource::initialize(layoutObject);
 
     if (m_styleImage->isImageResource())
         m_cachedImage = toStyleFetchedImage(m_styleImage)->cachedImage();
 
     m_styleImage->addClient(m_layoutObject);
 }
 
 void LayoutImageResourceStyleImage::shutdown()
 {
     ASSERT(m_layoutObject);
     m_styleImage->removeClient(m_layoutObject);
-    m_cachedImage = 0;
+    m_cachedImage = nullptr;
 }
 
 PassRefPtr<Image> LayoutImageResourceStyleImage::image(const IntSize& size, float zoom) const
 {
     // Generated content may trigger calls to image() while we're still pending, don't assert but gracefully exit.
     if (m_styleImage->isPendingImage())
         return nullptr;
     return m_styleImage->image(m_layoutObject, size, zoom);
 }
 
 DEFINE_TRACE(LayoutImageResourceStyleImage)
 {
     visitor->trace(m_styleImage);
     LayoutImageResource::trace(visitor);
 }
 
 } // namespace blink