Oilpan: LinkLoaderClient must be a GC mixin.

third_party/WebKit/Source/core/html/HTMLLinkElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Rob Buis (rwlbuis@gmail.com)
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 447 matching lines @@
     return m_sizes.get();
 }
 
 DEFINE_TRACE(HTMLLinkElement)
 {
     visitor->trace(m_link);
     visitor->trace(m_sizes);
     visitor->trace(m_linkLoader);
     visitor->trace(m_relList);
     HTMLElement::trace(visitor);
+    LinkLoaderClient::trace(visitor);
     DOMSettableTokenListObserver::trace(visitor);
 }
 
 PassOwnPtrWillBeRawPtr<LinkStyle> LinkStyle::create(HTMLLinkElement* owner)
 {
     return adoptPtrWillBeNoop(new LinkStyle(owner));
 }
 
 LinkStyle::LinkStyle(HTMLLinkElement* owner)
     : LinkResource(owner)
@@ skipping 310 matching lines @@
 }
 
 DEFINE_TRACE(LinkStyle)
 {
     visitor->trace(m_sheet);
     LinkResource::trace(visitor);
     ResourceOwner<StyleSheetResource>::trace(visitor);
 }
 
 } // namespace blink