Add support for the object-position CSS property.

Source/core/rendering/style/StyleRareNonInheritedData.h

Index: Source/core/rendering/style/StyleRareNonInheritedData.h
diff --git a/Source/core/rendering/style/StyleRareNonInheritedData.h b/Source/core/rendering/style/StyleRareNonInheritedData.h
index 340357a1505ce22f84175c1e3016d639e9781fde..bce9ff5e6916167f0294f46491b2767c3cc8c2b9 100644
--- a/Source/core/rendering/style/StyleRareNonInheritedData.h
+++ b/Source/core/rendering/style/StyleRareNonInheritedData.h
@@ -26,6 +26,7 @@
 #define StyleRareNonInheritedData_h
 
 #include "core/css/StyleColor.h"
+#include "core/platform/LengthPoint.h"
 #include "core/rendering/ClipPathOperation.h"
 #include "core/rendering/style/BasicShapes.h"
 #include "core/rendering/style/CounterDirectives.h"
@@ -142,6 +143,8 @@ public:
 
     int m_order;
 
+    LengthPoint m_objectPosition;
+
     AtomicString m_flowThread;
     AtomicString m_regionThread;
     unsigned m_regionFragment : 1; // RegionFragment