[css-grid] Fix a dangling reference

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 2062 matching lines @@
 }
 
 LayoutUnit LayoutGrid::assumedRowsSizeForOrthogonalChild(const LayoutBox& child, SizingOperation sizingOperation) const
 {
     DCHECK(isOrthogonalChild(child));
     const GridSpan& span = cachedGridSpan(child, ForRows);
     LayoutUnit gridAreaSize;
     bool gridAreaIsIndefinite = false;
     LayoutUnit containingBlockAvailableSize = containingBlockLogicalHeightForContent(ExcludeMarginBorderPadding);
     for (auto trackPosition : span) {
-        const GridLength& maxTrackSize = gridTrackSize(ForRows, trackPosition, sizingOperation).maxTrackBreadth();
+        GridLength maxTrackSize = gridTrackSize(ForRows, trackPosition, sizingOperation).maxTrackBreadth();
         if (maxTrackSize.isContentSized() || maxTrackSize.isFlex())
             gridAreaIsIndefinite = true;
         else
             gridAreaSize += valueForLength(maxTrackSize.length(), containingBlockAvailableSize);
     }
 
     gridAreaSize += guttersSize(ForRows, span.startLine(), span.integerSpan());
 
     return gridAreaIsIndefinite ? std::max(child.maxPreferredLogicalWidth(), gridAreaSize) : gridAreaSize;
 }
@@ skipping 562 matching lines @@
     return isOrthogonalChild(child) ? childLocation.transposedPoint() : childLocation;
 }
 
 void LayoutGrid::paintChildren(const PaintInfo& paintInfo, const LayoutPoint& paintOffset) const
 {
     if (!m_gridItemArea.isEmpty())
         GridPainter(*this).paintChildren(paintInfo, paintOffset);
 }
 
 } // namespace blink