Moving GraphicsContext and dependencies from core to platform.

Source/platform/scroll/ScrollbarThemeOverlay.h

Index: Source/platform/scroll/ScrollbarThemeOverlay.h
diff --git a/Source/core/platform/ScrollbarThemeOverlay.h b/Source/platform/scroll/ScrollbarThemeOverlay.h
similarity index 96%
rename from Source/core/platform/ScrollbarThemeOverlay.h
rename to Source/platform/scroll/ScrollbarThemeOverlay.h
index 0a7e2d1639d5258a85f3e06897b89e4a34217a94..5bc8e770bea2aaec9a71470c9fddbc308cbee8d4 100644
--- a/Source/core/platform/ScrollbarThemeOverlay.h
+++ b/Source/platform/scroll/ScrollbarThemeOverlay.h
@@ -26,13 +26,13 @@
 #ifndef ScrollbarThemeOverlay_h
 #define ScrollbarThemeOverlay_h
 
-#include "core/platform/ScrollbarTheme.h"
+#include "platform/scroll/ScrollbarTheme.h"
 
 namespace WebCore {
 
 // This scrollbar theme is used to get overlay scrollbar for platforms other
 // than Mac. Mac's overlay scrollbars are in ScrollbarThemeMac*.
-class ScrollbarThemeOverlay : public ScrollbarTheme {
+class PLATFORM_EXPORT ScrollbarThemeOverlay : public ScrollbarTheme {
 public:
     enum HitTestBehavior { AllowHitTest, DisallowHitTest };