Add parsing for named grid lines

Source/core/rendering/RenderGrid.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 843 matching lines @@
     if (resolvedFinalPosition < resolvedInitialPosition)
         resolvedFinalPosition = resolvedInitialPosition;
 
     return adoptPtr(new GridSpan(resolvedInitialPosition, resolvedFinalPosition));
 }
 
 size_t RenderGrid::resolveGridPositionFromStyle(const GridPosition& position, GridPositionSide side) const
 {
     // FIXME: Handle other values for grid-{row,column} like ranges or line names.
     switch (position.type()) {
-    case IntegerPosition: {
+    case ExplicitPosition: {
         if (position.isPositive()) {
             if (side == EndSide || side == AfterSide)
                 return std::max(0, position.integerPosition() - 2);
 
             return position.integerPosition() - 1;
         }
 
         size_t resolvedPosition = abs(position.integerPosition());
         // FIXME: This returns one less than the expected result for side == StartSide or BeforeSide as we don't properly convert
         // the grid line to its grid track. However this avoids the issue of growing the grid when inserting the item (e.g. -1 / auto).
@@ skipping 70 matching lines @@
     if (isOutOfFlowPositioned())
         return "RenderGrid (positioned)";
     if (isAnonymous())
         return "RenderGrid (generated)";
     if (isRelPositioned())
         return "RenderGrid (relative positioned)";
     return "RenderGrid";
 }
 
 } // namespace WebCore