Replace various ScrollableArea scroll methods with setScrollPosition

Source/platform/scroll/ScrollTypes.h

 /*
  * Copyright (C) 2006 Apple Computer, 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 31 matching lines @@
     ScrollInlineDirectionForward
 };
 
 enum ScrollDirectionPhysical {
     ScrollUp,
     ScrollDown,
     ScrollLeft,
     ScrollRight
 };
 
+enum ScrollType {
+    UserScroll,
+    ProgrammaticScroll,
+    CompositorScroll
+};
+
 // Convert logical scroll direction to physical. Physical scroll directions are unaffected.
 inline ScrollDirectionPhysical toPhysicalDirection(ScrollDirection direction, bool isVertical, bool isFlipped)
 {
     switch (direction) {
     case ScrollBlockDirectionBackward: {
         if (isVertical) {
             if (!isFlipped)
                 return ScrollUp;
             return ScrollDown;
         }
@@ skipping 143 matching lines @@
     bool didScroll;
     float unusedScrollDeltaX;
     float unusedScrollDeltaY;
 };
 
 typedef unsigned ScrollbarControlPartMask;
 
 }
 
 #endif