Have EditCommand classes deal with Document references, not pointers

Source/core/editing/UnlinkCommand.cpp

 /*
  * Copyright (C) 2006 Apple Computer, 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 12 matching lines @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "core/editing/UnlinkCommand.h"
 
 #include "core/html/HTMLAnchorElement.h"
 
 namespace WebCore {
 
-UnlinkCommand::UnlinkCommand(Document* document)
+UnlinkCommand::UnlinkCommand(Document& document)
     : CompositeEditCommand(document)
 {
 }
 
 void UnlinkCommand::doApply()
 {
     // FIXME: If a caret is inside a link, we should remove it, but currently we don't.
     if (!endingSelection().isNonOrphanedRange())
         return;
 
-    removeStyledElement(HTMLAnchorElement::create(document()));
+    removeStyledElement(HTMLAnchorElement::create(&document()));
 }
 
 }