Oilpan: Remove guardRef and guardDeref from TreeScope.

Source/core/dom/DocumentMarkerController.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 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 353 matching lines @@
         m_markers.remove(node);
         if (m_markers.isEmpty())
             m_possiblyExistingMarkerTypes = 0;
     }
 
     // repaint the affected node
     if (docDirty && node->renderer())
         node->renderer()->repaint();
 }
 
+void DocumentMarkerController::clearWeakMembers(Visitor* visitor)
+{
+    Vector<const Node*> deadNodes;
+    for (MarkerMap::iterator it = m_markers.begin(); it != m_markers.end(); ++it) {
+        if (!visitor->isAlive(it->key))
+            deadNodes.append(it->key);
+    }
+    for (unsigned i = 0; i < deadNodes.size(); ++i)
+        removeMarkers(const_cast<Node*>(deadNodes[i]));
+}
+
 DocumentMarker* DocumentMarkerController::markerContainingPoint(const LayoutPoint& point, DocumentMarker::MarkerType markerType)
 {
     if (!possiblyHasMarkers(markerType))
         return 0;
     ASSERT(!(m_markers.isEmpty()));
 
     // outer loop: process each node that contains any markers
     MarkerMap::iterator end = m_markers.end();
     for (MarkerMap::iterator nodeIterator = m_markers.begin(); nodeIterator != end; ++nodeIterator) {
         // inner loop; process each marker in this node
@@ skipping 351 matching lines @@
 
 } // namespace WebCore
 
 #ifndef NDEBUG
 void showDocumentMarkers(const WebCore::DocumentMarkerController* controller)
 {
     if (controller)
         controller->showMarkers();
 }
 #endif