Have TreeScrope::adoptIfNeeded() take a reference instead of a pointer

Source/core/dom/TreeScope.cpp

 /*
  * Copyright (C) 2011 Google Inc. All Rights Reserved.
  * Copyright (C) 2012 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
@@ skipping 315 matching lines @@
         }
     }
     return 0;
 }
 
 bool TreeScope::applyAuthorStyles() const
 {
     return !rootNode()->isShadowRoot() || toShadowRoot(rootNode())->applyAuthorStyles();
 }
 
-void TreeScope::adoptIfNeeded(Node* node)
+void TreeScope::adoptIfNeeded(Node& node)
 {
     ASSERT(this);
-    ASSERT(node);
-    ASSERT(!node->isDocumentNode());
-    ASSERT_WITH_SECURITY_IMPLICATION(!node->m_deletionHasBegun);
-    TreeScopeAdopter adopter(node, this);
+    ASSERT(!node.isDocumentNode());
+    ASSERT_WITH_SECURITY_IMPLICATION(!node.m_deletionHasBegun);
+    TreeScopeAdopter adopter(node, *this);
     if (adopter.needsScopeChange())
         adopter.execute();
 }
 
 static Element* focusedFrameOwnerElement(Frame* focusedFrame, Frame* currentFrame)
 {
     for (; focusedFrame; focusedFrame = focusedFrame->tree().parent()) {
         if (focusedFrame->tree().parent() == currentFrame)
             return focusedFrame->ownerElement();
     }
@@ skipping 138 matching lines @@
             result = element;
         for (ShadowRoot* shadowRoot = element->youngestShadowRoot(); shadowRoot; shadowRoot = shadowRoot->olderShadowRoot()) {
             if (Element* shadowResult = shadowRoot->getElementByAccessKey(key))
                 result = shadowResult;
         }
     }
     return result;
 }
 
 } // namespace WebCore