Moving GraphicsContext and dependencies from core to platform.

Source/platform/mac/ColorMac.h

Index: Source/platform/mac/ColorMac.h
diff --git a/Source/core/platform/graphics/mac/ColorMac.h b/Source/platform/mac/ColorMac.h
similarity index 86%
rename from Source/core/platform/graphics/mac/ColorMac.h
rename to Source/platform/mac/ColorMac.h
index 24b36488e015ec53a22f484753b89d324a07e9a9..3836a3882950a8d52cb722fb8a6060f98fd855e5 100644
--- a/Source/core/platform/graphics/mac/ColorMac.h
+++ b/Source/platform/mac/ColorMac.h
@@ -36,14 +36,14 @@ 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();
 
 }