Have StyleSheetCollections constructor take a Document reference in argument

Source/core/dom/DocumentStyleSheetCollection.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 27 matching lines @@
 #include "core/html/HTMLIFrameElement.h"
 #include "core/html/HTMLLinkElement.h"
 #include "core/html/HTMLStyleElement.h"
 #include "core/page/Settings.h"
 #include "core/svg/SVGStyleElement.h"
 
 namespace WebCore {
 
 using namespace HTMLNames;
 
-DocumentStyleSheetCollection::DocumentStyleSheetCollection(TreeScope* treeScope)
+DocumentStyleSheetCollection::DocumentStyleSheetCollection(TreeScope& treeScope)
     : StyleSheetCollection(treeScope)
 {
-    ASSERT(treeScope->rootNode() == &treeScope->rootNode()->document());
+    ASSERT(treeScope.rootNode() == &treeScope.rootNode()->document());
 }
 
 void DocumentStyleSheetCollection::collectStyleSheets(StyleSheetCollections* collections, Vector<RefPtr<StyleSheet> >& styleSheets, Vector<RefPtr<CSSStyleSheet> >& activeSheets)
 {
     if (document()->settings() && !document()->settings()->authorAndUserStylesEnabled())
         return;
 
     DocumentOrderedList::iterator begin = m_styleSheetCandidateNodes.begin();
     DocumentOrderedList::iterator end = m_styleSheetCandidateNodes.end();
     for (DocumentOrderedList::iterator it = begin; it != end; ++it) {
@@ skipping 115 matching lines @@
     }
     m_scopingNodesForStyleScoped.didRemoveScopingNodes();
     m_activeAuthorStyleSheets.swap(activeCSSStyleSheets);
     m_styleSheetsForStyleSheetList.swap(styleSheets);
     updateUsesRemUnits();
 
     return requiresFullStyleRecalc;
 }
 
 }