Allow grid positions to be named grid areas

Source/core/rendering/style/GridPosition.h

 /*
  * Copyright (C) 2012 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 20 matching lines @@
 #ifndef GridPosition_h
 #define GridPosition_h
 
 #include "wtf/text/WTFString.h"
 
 namespace WebCore {
 
 enum GridPositionType {
     AutoPosition,
     ExplicitPosition, // [ <integer> || <string> ]
-    SpanPosition
+    SpanPosition, // span && [ <integer> || <string> ]
+    NamedGridAreaPosition // <ident>
 };
 
 class GridPosition {
 public:
     GridPosition()
         : m_type(AutoPosition)
         , m_integerPosition(0)
     {
     }
 
     bool isPositive() const { return integerPosition() > 0; }
 
     GridPositionType type() const { return m_type; }
     bool isAuto() const { return m_type == AutoPosition; }
     bool isSpan() const { return m_type == SpanPosition; }
+    bool isNamedGridArea() const { return m_type == NamedGridAreaPosition; }
 
     void setExplicitPosition(int position, const String& namedGridLine)
     {
         m_type = ExplicitPosition;
         m_integerPosition = position;
         m_namedGridLine = namedGridLine;
     }
 
     // 'span' values cannot be negative, yet we reuse the <integer> position which can
     // be. This means that we have to convert the span position to an integer, losing
     // some precision here. It shouldn't be an issue in practice though.
     void setSpanPosition(int position, const String& namedGridLine)
     {
         m_type = SpanPosition;
         m_integerPosition = position;
         m_namedGridLine = namedGridLine;
     }
 
+    void setNamedGridArea(const String& namedGridArea)
+    {
+        m_type = NamedGridAreaPosition;
+        m_namedGridLine = namedGridArea;
+    }
+
     int integerPosition() const
     {
         ASSERT(type() == ExplicitPosition);
         return m_integerPosition;
     }
 
     String namedGridLine() const
     {
-        ASSERT(type() == ExplicitPosition || type() == SpanPosition);
+        ASSERT(type() == ExplicitPosition || type() == SpanPosition || type() == NamedGridAreaPosition);
         return m_namedGridLine;
     }
 
     int spanPosition() const
     {
         ASSERT(type() == SpanPosition);
         return m_integerPosition;
     }
 
     bool operator==(const GridPosition& other) const
     {
         return m_type == other.m_type && m_integerPosition == other.m_integerPosition && m_namedGridLine == other.m_namedGridLine;
     }
 
     bool shouldBeResolvedAgainstOppositePosition() const
     {
         return isAuto() || isSpan();
     }
 private:
     GridPositionType m_type;
     int m_integerPosition;
     String m_namedGridLine;
 };
 
 } // namespace WebCore
 
 #endif // GridPosition_h