Use more references in ContainerNode code

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 2831 matching lines @@
     KURL mediaURL;
     Node* node;
     HTMLSourceElement* source = 0;
     String type;
     String system;
     bool lookingForStartNode = m_nextChildNodeToConsider;
     bool canUseSourceElement = false;
     bool okToLoadSourceURL;
 
     NodeVector potentialSourceNodes;
-    getChildNodes(this, potentialSourceNodes);
+    getChildNodes(*this, potentialSourceNodes);
 
     for (unsigned i = 0; !canUseSourceElement && i < potentialSourceNodes.size(); ++i) {
         node = potentialSourceNodes[i].get();
         if (lookingForStartNode && m_nextChildNodeToConsider != node)
             continue;
         lookingForStartNode = false;
 
         if (!node->hasTagName(sourceTag))
             continue;
         if (node->parentNode() != this)
@@ skipping 1007 matching lines @@
 {
     scheduleLayerUpdate();
 }
 
 bool HTMLMediaElement::isInteractiveContent() const
 {
     return fastHasAttribute(controlsAttr);
 }
 
 }