Remove some unnecessary using namespaces and add include guards

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

 /*
  * Copyright (C) 2011 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
@@ skipping 35 matching lines @@
   ContentAlignmentData(){};
   ContentAlignmentData(LayoutUnit position, LayoutUnit distribution)
       : positionOffset(position), distributionOffset(distribution) {}
 
   bool isValid() { return positionOffset >= 0 && distributionOffset >= 0; }
 
   LayoutUnit positionOffset = LayoutUnit(-1);
   LayoutUnit distributionOffset = LayoutUnit(-1);
 };
 
-enum TrackSizeRestriction {
-  AllowInfinity,
-  ForbidInfinity,
-};
-
 LayoutGrid::LayoutGrid(Element* element)
     : LayoutBlock(element), m_grid(this), m_trackSizingAlgorithm(this, m_grid) {
   ASSERT(!childrenInline());
   if (!isAnonymous())
     UseCounter::count(document(), UseCounter::CSSGridLayout);
 }
 
 LayoutGrid::~LayoutGrid() {}
 
 LayoutGrid* LayoutGrid::createAnonymous(Document* document) {
@@ skipping 2020 matching lines @@
   if (direction == ForRows)
     return grid.numTracks(ForRows);
 
   return grid.numTracks(ForRows)
              ? grid.numTracks(ForColumns)
              : GridPositionsResolver::explicitGridColumnCount(
                    styleRef(), grid.autoRepeatTracks(ForColumns));
 }
 
 }  // namespace blink