Remove some unnecessary using namespaces and add include guards

third_party/WebKit/Source/core/layout/LayoutFieldset.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006 Apple Computer, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 10 matching lines @@
  *
  */
 
 #include "core/layout/LayoutFieldset.h"
 
 #include "core/CSSPropertyNames.h"
 #include "core/HTMLNames.h"
 #include "core/html/HTMLLegendElement.h"
 #include "core/paint/FieldsetPainter.h"
 
-using namespace std;
-
 namespace blink {
 
 using namespace HTMLNames;
 
 LayoutFieldset::LayoutFieldset(Element* element) : LayoutBlockFlow(element) {}
 
 void LayoutFieldset::computePreferredLogicalWidths() {
   LayoutBlockFlow::computePreferredLogicalWidths();
   if (LayoutBox* legend = findInFlowLegend()) {
     int legendMinWidth = legend->minPreferredLogicalWidth().toInt();
@@ skipping 111 matching lines @@
     const LayoutPoint& paintOffset) const {
   FieldsetPainter(*this).paintBoxDecorationBackground(paintInfo, paintOffset);
 }
 
 void LayoutFieldset::paintMask(const PaintInfo& paintInfo,
                                const LayoutPoint& paintOffset) const {
   FieldsetPainter(*this).paintMask(paintInfo, paintOffset);
 }
 
 }  // namespace blink