Remove some unnecessary using namespaces and add include guards

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc.
  *               All rights reserved.
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 15 matching lines @@
 
 #include "core/layout/LayoutBlockFlow.h"
 #include "core/layout/LayoutBox.h"
 #include "core/layout/LayoutView.h"
 #include "core/layout/api/LineLayoutBlockFlow.h"
 #include "core/layout/shapes/ShapeOutsideInfo.h"
 #include "wtf/PtrUtil.h"
 #include <algorithm>
 #include <memory>
 
-using namespace WTF;
-
 namespace blink {
 
 struct SameSizeAsFloatingObject {
   void* pointers[2];
   LayoutRect rect;
   uint32_t bitfields : 8;
 };
 
 static_assert(sizeof(FloatingObject) == sizeof(SameSizeAsFloatingObject),
               "FloatingObject should stay small");
@@ skipping 678 matching lines @@
     const FloatingObject* floatingObject) {
   return String::format("%p (%gx%g %gx%g)", floatingObject,
                         floatingObject->frameRect().x().toFloat(),
                         floatingObject->frameRect().y().toFloat(),
                         floatingObject->frameRect().maxX().toFloat(),
                         floatingObject->frameRect().maxY().toFloat());
 }
 #endif
 
 }  // namespace blink