Remove duplicated headers from core/

Source/core/html/shadow/DateTimeNumericFieldElement.cpp

 /*
  * Copyright (C) 2012 Google 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 14 matching lines @@
 
 #include "config.h"
 #if ENABLE(INPUT_MULTIPLE_FIELDS_UI)
 #include "core/html/shadow/DateTimeNumericFieldElement.h"
 
 #include "CSSPropertyNames.h"
 #include "CSSValueKeywords.h"
 #include "core/events/KeyboardEvent.h"
 #include "core/platform/graphics/Font.h"
 #include "platform/text/PlatformLocale.h"
-#include "wtf/text/StringBuilder.h"
 
 using namespace WTF::Unicode;
 
 namespace WebCore {
 
 static const DOMTimeStamp typeAheadTimeout = 1000;
 
 int DateTimeNumericFieldElement::Range::clampValue(int value) const
 {
     return std::min(std::max(value, minimum), maximum);
@@ skipping 192 matching lines @@
     if (n >= 0)
         n = (n + m_step.step - 1) / m_step.step * m_step.step;
     else
         n = -(-n / m_step.step * m_step.step);
     return n + m_step.stepBase;
 }
 
 } // namespace WebCore
 
 #endif