[Mac] Rely on science, not chance, to get the proper definition of the macro

Source/platform/geometry/IntPoint.h

 /*
  * Copyright (C) 2004, 2005, 2006 Apple Computer, Inc.  All rights reserved.
  * Copyright (C) 2013 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:
  * 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
@@ skipping 14 matching lines @@
  */
 
 #ifndef IntPoint_h
 #define IntPoint_h
 
 #include "platform/geometry/IntSize.h"
 #include "wtf/MathExtras.h"
 
 #if OS(MACOSX)
 typedef struct CGPoint CGPoint;
-#ifdef NSGEOMETRY_TYPES_SAME_AS_CGGEOMETRY_TYPES
-typedef struct CGPoint NSPoint;
-#else
-typedef struct _NSPoint NSPoint;
+
+#ifdef __OBJC__
+#import <Foundation/Foundation.h>
 #endif
 #endif
 
 namespace WebCore {
 
 class PLATFORM_EXPORT IntPoint {
 public:
     IntPoint() : m_x(0), m_y(0) { }
     IntPoint(int x, int y) : m_x(x), m_y(y) { }
     explicit IntPoint(const IntSize& size) : m_x(size.width()), m_y(size.height()) { }
@@ skipping 36 matching lines @@
 
     IntPoint transposedPoint() const
     {
         return IntPoint(m_y, m_x);
     }
 
 #if OS(MACOSX)
     explicit IntPoint(const CGPoint&); // don't do this implicitly since it's lossy
     operator CGPoint() const;
 
-#if !defined(NSGEOMETRY_TYPES_SAME_AS_CGGEOMETRY_TYPES)
+#if defined(__OBJC__) && !defined(NSGEOMETRY_TYPES_SAME_AS_CGGEOMETRY_TYPES)
     explicit IntPoint(const NSPoint&); // don't do this implicitly since it's lossy
     operator NSPoint() const;
 #endif
 #endif
 
 private:
     int m_x, m_y;
 };
 
 inline IntPoint& operator+=(IntPoint& a, const IntSize& b)
@@ skipping 49 matching lines @@
 }
 
 inline int IntPoint::distanceSquaredToPoint(const IntPoint& point) const
 {
     return ((*this) - point).diagonalLengthSquared();
 }
 
 } // namespace WebCore
 
 #endif // IntPoint_h