Remove ~1750 superfluous includes from core

Source/core/platform/Scrollbar.cpp

 /*
  * Copyright (C) 2004, 2006, 2008 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 18 matching lines @@
 #include <algorithm>
 #include "core/platform/PlatformGestureEvent.h"
 #include "core/platform/PlatformMouseEvent.h"
 #include "core/platform/ScrollAnimator.h"
 #include "core/platform/ScrollableArea.h"
 #include "core/platform/ScrollbarTheme.h"
 #include "core/platform/graphics/GraphicsContext.h"
 
 // FIXME: The following #includes are a layering violation and should be removed.
 #include "core/accessibility/AXObjectCache.h"
-#include "core/accessibility/AccessibilityScrollbar.h"
-#include "core/dom/Document.h"
 #include "core/page/EventHandler.h"
 #include "core/page/Frame.h"
 #include "core/page/FrameView.h"
 
 using namespace std;
 
 #if OS(UNIX) && !OS(DARWIN)
 // The position of the scrollbar thumb affects the appearance of the steppers, so
 // when the thumb moves, we have to invalidate them for painting.
 #define THUMB_POSITION_AFFECTS_BUTTONS
@@ skipping 546 matching lines @@
 
 IntPoint Scrollbar::convertFromContainingView(const IntPoint& parentPoint) const
 {
     if (m_scrollableArea)
         return m_scrollableArea->convertFromContainingViewToScrollbar(this, parentPoint);
 
     return Widget::convertFromContainingView(parentPoint);
 }
 
 } // namespace WebCore