Remove unnecessary Document.h includes in .cpp files

Source/core/editing/InsertNodeBeforeCommand.cpp

 /*
  * Copyright (C) 2005, 2008 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
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "core/editing/InsertNodeBeforeCommand.h"
 
 #include "bindings/v8/ExceptionStatePlaceholder.h"
-#include "core/dom/Document.h"
 
 namespace WebCore {
 
 InsertNodeBeforeCommand::InsertNodeBeforeCommand(PassRefPtrWillBeRawPtr<Node> insertChild, PassRefPtrWillBeRawPtr<Node> refChild,
     ShouldAssumeContentIsAlwaysEditable shouldAssumeContentIsAlwaysEditable)
     : SimpleEditCommand(refChild->document())
     , m_insertChild(insertChild)
     , m_refChild(refChild)
     , m_shouldAssumeContentIsAlwaysEditable(shouldAssumeContentIsAlwaysEditable)
 {
@@ skipping 24 matching lines @@
 }
 
 void InsertNodeBeforeCommand::trace(Visitor* visitor)
 {
     visitor->trace(m_insertChild);
     visitor->trace(m_refChild);
     SimpleEditCommand::trace(visitor);
 }
 
 }