[oilpan] Wrap NodeVector into CollectionRoot for ensure that contained nodes stay alive.

Source/core/html/HTMLMediaElement.cpp

 /*
  * Copyright (C) 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 3055 matching lines @@
     Handle<HTMLSourceElement> source;
     String type;
     String system;
     bool lookingForStartNode = m_nextChildNodeToConsider;
     bool canUseSourceElement = false;
     bool okToLoadSourceURL;
 
     NodeVector potentialSourceNodes;
     getChildNodes(this, potentialSourceNodes);
 
-    for (unsigned i = 0; !canUseSourceElement && i < potentialSourceNodes.size(); ++i) {
+    for (unsigned i = 0; !canUseSourceElement && i < potentialSourceNodes->size(); ++i) {
         HandleScope scope;
         node = potentialSourceNodes[i];
         if (lookingForStartNode && m_nextChildNodeToConsider != node.raw())
             continue;
         lookingForStartNode = false;
 
         if (!node->hasTagName(sourceTag))
             continue;
         if (node->parentNode() != this)
             continue;
@@ skipping 1378 matching lines @@
 }
 
 void HTMLMediaElement::accept(Visitor* visitor) const
 {
     visitor->visit(m_currentSourceNode);
     HTMLElement::accept(visitor);
 }
 
 }