Moving GraphicsContext and dependencies from core to platform.

Source/platform/scroll/ScrollableArea.h

Index: Source/platform/scroll/ScrollableArea.h
diff --git a/Source/core/platform/ScrollableArea.h b/Source/platform/scroll/ScrollableArea.h
similarity index 98%
rename from Source/core/platform/ScrollableArea.h
rename to Source/platform/scroll/ScrollableArea.h
index 1dc7b2eb9b3e1bd636e3543f17e6557b75f5fba9..c3a6aa9eded6f56696afcd5e14c33d717eea65de 100644
--- a/Source/core/platform/ScrollableArea.h
+++ b/Source/platform/scroll/ScrollableArea.h
@@ -26,7 +26,10 @@
 #ifndef ScrollableArea_h
 #define ScrollableArea_h
 
-#include "core/platform/Scrollbar.h"
+#include "platform/PlatformExport.h"
+#include "platform/scroll//ScrollAnimator.h"
+#include "platform/scroll/Scrollbar.h"
+#include "wtf/Noncopyable.h"
 #include "wtf/Vector.h"
 
 namespace WebCore {
@@ -38,7 +41,8 @@ class PlatformGestureEvent;
 class PlatformWheelEvent;
 class ScrollAnimator;
 
-class ScrollableArea {
+class PLATFORM_EXPORT ScrollableArea {
+    WTF_MAKE_NONCOPYABLE(ScrollableArea);
 public:
     static int pixelsPerLineStep();
     static float minFractionToStepWhenPaging();