Add support for 'order' on grid items

Source/core/rendering/OrderIterator.h

Index: Source/core/rendering/OrderIterator.h
diff --git a/Source/core/rendering/OrderIterator.h b/Source/core/rendering/OrderIterator.h
index 9c36d7f489ee0d54f396774402faefe4dd9ed008..cfbacb7199583e9f7507c87c913215f5f26926a5 100644
--- a/Source/core/rendering/OrderIterator.h
+++ b/Source/core/rendering/OrderIterator.h
@@ -38,11 +38,14 @@ namespace WebCore {
 
 class RenderBox;
 class RenderFlexibleBox;
+class RenderGrid;
 
 class OrderIterator {
     WTF_MAKE_NONCOPYABLE(OrderIterator);
 public:
     OrderIterator(const RenderFlexibleBox*);
+    OrderIterator(const RenderGrid*);

[ojan, 2013/07/03 20:21:57]

Lets just have it take a const RenderBox* instead of having multiple
constructors. In theory, we'll eventually support order on other RenderBox types
as well (e.g. display:block).

[Julien - ping for review, 2013/07/03 21:38:16]

Done.

+
     void setOrderValues(Vector<int>&);
     RenderBox* currentChild() const { return m_currentChild; }
     RenderBox* first();
@@ -50,7 +53,7 @@ public:
     void reset();
 
 private:
-    const RenderFlexibleBox* m_flexibleBox;
+    const RenderBox* m_containerBox;
     RenderBox* m_currentChild;
     Vector<int> m_orderValues;
     Vector<int>::const_iterator m_orderValuesIterator;