Revert "Reworks the clipping logic" and follow-up.

Source/core/layout/ClipRect.h

 /*
  * Copyright (C) 2003, 2009, 2012 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 10 matching lines @@
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef ClipRect_h
 #define ClipRect_h
 
 #include "platform/geometry/LayoutRect.h"
 #include "wtf/FastAllocBase.h"
-#include "wtf/PassOwnPtr.h"
 
 namespace blink {
 
-class DeprecatedPaintLayer;
 class HitTestLocation;
 
 class ClipRect {
     WTF_MAKE_FAST_ALLOCATED(ClipRect);
 public:
-    static PassOwnPtr<ClipRect> create(const ClipRect& other)
-    {
-        return adoptPtr(new ClipRect(other));
-    }
-
     ClipRect()
         : m_hasRadius(false)
     { }
 
     ClipRect(const LayoutRect& rect)
         : m_rect(rect)
         , m_hasRadius(false)
     { }
 
     const LayoutRect& rect() const { return m_rect; }
@@ skipping 12 matching lines @@
         if (other.hasRadius())
             m_hasRadius = true;
     }
     void move(const LayoutSize& size) { m_rect.move(size); }
     void move(const IntSize& size) { m_rect.move(size); }
     void moveBy(const LayoutPoint& point) { m_rect.moveBy(point); }
 
     bool isEmpty() const { return m_rect.isEmpty(); }
     bool intersects(const HitTestLocation&) const;
 
-    const DeprecatedPaintLayer* rootLayer() const
-    {
-        return m_rootLayer;
-    }
-
-    void setRootLayer(const DeprecatedPaintLayer* rootLayer)
-    {
-        m_rootLayer = rootLayer;
-    }
-
 private:
-    const DeprecatedPaintLayer* m_rootLayer;
     LayoutRect m_rect;
     bool m_hasRadius;
 };
 
 inline ClipRect intersection(const ClipRect& a, const ClipRect& b)
 {
     ClipRect c = a;
     c.intersect(b);
     return c;
 }
 
 } // namespace blink
 
 #endif // ClipRect_h