Rename OS(DARWIN) to OS(MACOSX).

Source/core/page/scrolling/ScrollingCoordinator.h

 /*
  * Copyright (C) 2011 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 58 matching lines @@
 
     // Should be called whenever the slow repaint objects counter changes between zero and one.
     void frameViewHasSlowRepaintObjectsDidChange(FrameView*);
 
     // Should be called whenever the set of fixed objects changes.
     void frameViewFixedObjectsDidChange(FrameView*);
 
     // Should be called whenever the root layer for the given frame view changes.
     void frameViewRootLayerDidChange(FrameView*);
 
-#if OS(DARWIN)
+#if OS(MACOSX)
     // Dispatched by the scrolling tree during handleWheelEvent. This is required as long as scrollbars are painted on the main thread.
     void handleWheelEventPhase(PlatformWheelEventPhase);
 #endif
 
     enum MainThreadScrollingReasonFlags {
         HasSlowRepaintObjects = 1 << 0,
         HasViewportConstrainedObjectsWithoutSupportingFixedLayers = 1 << 1,
         HasNonLayerViewportConstrainedObjects = 1 << 2,
     };
 
@@ skipping 51 matching lines @@
 
     typedef HashMap<ScrollableArea*, OwnPtr<WebKit::WebScrollbarLayer> > ScrollbarMap;
     ScrollbarMap m_horizontalScrollbars;
     ScrollbarMap m_verticalScrollbars;
     HashSet<const RenderLayer*> m_layersWithTouchRects;
 };
 
 } // namespace WebCore
 
 #endif // ScrollingCoordinator_h