Moving GraphicsContext and dependencies from core to platform.

Source/platform/mac/ColorMac.h

 /*
  * Copyright (C) 2007 Apple 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 18 matching lines @@
 #ifndef ColorMac_h
 #define ColorMac_h
 
 #include "platform/graphics/Color.h"
 
 OBJC_CLASS NSColor;
 
 namespace WebCore {
 
     // These functions assume NSColors are in DeviceRGB colorspace
-    Color colorFromNSColor(NSColor *);
-    NSColor *nsColor(const Color&);
+    Color PLATFORM_EXPORT colorFromNSColor(NSColor *);
+    NSColor* PLATFORM_EXPORT nsColor(const Color&);
 
-    bool usesTestModeFocusRingColor();
-    void setUsesTestModeFocusRingColor(bool);
+    bool PLATFORM_EXPORT usesTestModeFocusRingColor();
+    void PLATFORM_EXPORT setUsesTestModeFocusRingColor(bool);
 
     // Focus ring color used for testing purposes.
-    RGBA32 oldAquaFocusRingColor();
+    RGBA32 PLATFORM_EXPORT oldAquaFocusRingColor();
 
 }
 
 #endif