Make stylesheet owner node a reference instead of pointer.

third_party/WebKit/Source/core/dom/TreeScopeStyleSheetCollection.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
@@ skipping 26 matching lines @@
 #include "core/html/HTMLStyleElement.h"
 
 namespace blink {
 
 TreeScopeStyleSheetCollection::TreeScopeStyleSheetCollection(TreeScope& treeScope)
     : m_treeScope(treeScope)
     , m_hadActiveLoadingStylesheet(false)
 {
 }
 
-void TreeScopeStyleSheetCollection::addStyleSheetCandidateNode(Node* node)
+void TreeScopeStyleSheetCollection::addStyleSheetCandidateNode(Node& node)
 {
-    if (!node->isConnected())
+    if (!node.isConnected())
         return;
 
-    m_styleSheetCandidateNodes.add(node);
+    m_styleSheetCandidateNodes.add(&node);
 }
 
 TreeScopeStyleSheetCollection::StyleResolverUpdateType TreeScopeStyleSheetCollection::compareStyleSheets(const HeapVector<Member<CSSStyleSheet>>& oldStyleSheets, const HeapVector<Member<CSSStyleSheet>>& newStylesheets, HeapVector<Member<StyleSheetContents>>& addedSheets)
 {
     unsigned newStyleSheetCount = newStylesheets.size();
     unsigned oldStyleSheetCount = oldStyleSheets.size();
     DCHECK_GE(newStyleSheetCount, oldStyleSheetCount);
 
     if (!newStyleSheetCount)
         return Reconstruct;
@@ skipping 105 matching lines @@
 }
 
 DEFINE_TRACE(TreeScopeStyleSheetCollection)
 {
     visitor->trace(m_treeScope);
     visitor->trace(m_styleSheetCandidateNodes);
     StyleSheetCollection::trace(visitor);
 }
 
 } // namespace blink