Move the Widget hierarchy to the Oilpan heap.

Source/core/rendering/HitTestResult.cpp

 /*
  * Copyright (C) 2006, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 101 matching lines @@
 
     return *this;
 }
 
 void HitTestResult::trace(Visitor* visitor)
 {
     visitor->trace(m_innerNode);
     visitor->trace(m_innerPossiblyPseudoNode);
     visitor->trace(m_innerNonSharedNode);
     visitor->trace(m_innerURLElement);
+    visitor->trace(m_scrollbar);
 #if ENABLE(OILPAN)
     visitor->trace(m_rectBasedTestResult);
 #endif
 }
 
 PositionWithAffinity HitTestResult::position() const
 {
     if (!m_innerPossiblyPseudoNode)
         return PositionWithAffinity();
     RenderObject* renderer = this->renderer();
@@ skipping 341 matching lines @@
 {
     for (Node* node = m_innerNode.get(); node; node = NodeRenderingTraversal::parent(node)) {
         if (node->isElementNode())
             return toElement(node);
     }
 
     return 0;
 }
 
 } // namespace blink