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 07c7bd365e70777056ebf3261d4e0b58d7d637fe..07f929324815769fa2781283067b98922337eab4 100644
--- a/Source/core/rendering/style/StyleRareNonInheritedData.h
+++ b/Source/core/rendering/style/StyleRareNonInheritedData.h
@@ -25,6 +25,7 @@
 #ifndef StyleRareNonInheritedData_h
 #define StyleRareNonInheritedData_h
 
+#include "core/platform/LengthPoint.h"
 #include "core/rendering/ClipPathOperation.h"
 #include "core/rendering/style/BasicShapes.h"
 #include "core/rendering/style/CounterDirectives.h"
@@ -143,6 +144,8 @@ public:
 
     int m_order;
 
+    LengthPoint m_objectPosition;
+
     AtomicString m_flowThread;
     AtomicString m_regionThread;
     unsigned m_regionFragment : 1; // RegionFragment