Remove duplicated headers from core/

Source/core/dom/StyleSheetCollection.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
@@ skipping 14 matching lines @@
  */
 
 #include "config.h"
 #include "core/dom/StyleSheetCollection.h"
 
 #include "core/css/CSSStyleSheet.h"
 #include "core/css/StyleInvalidationAnalysis.h"
 #include "core/css/StyleRuleImport.h"
 #include "core/css/StyleSheetContents.h"
 #include "core/css/resolver/StyleResolver.h"
-#include "core/dom/Document.h"
 #include "core/dom/Element.h"
 #include "core/dom/StyleEngine.h"
 #include "core/html/HTMLStyleElement.h"
 #include "core/page/Settings.h"
 
 namespace WebCore {
 
 StyleSheetCollectionBase::StyleSheetCollectionBase()
 {
 }
@@ skipping 200 matching lines @@
     }
     return false;
 }
 
 void StyleSheetCollection::updateUsesRemUnits()
 {
     m_usesRemUnits = styleSheetsUseRemUnits(m_activeAuthorStyleSheets);
 }
 
 }