Remove clips where we can show that they are unnecessary.

Source/core/rendering/RenderOverflow.h

 /*
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 30 matching lines @@
     WTF_MAKE_NONCOPYABLE(RenderOverflow); WTF_MAKE_FAST_ALLOCATED;
 public:
     RenderOverflow(const LayoutRect& layoutRect, const LayoutRect& visualRect)
         : m_layoutOverflow(layoutRect)
         , m_visualOverflow(visualRect)
     {
     }
 
     const LayoutRect layoutOverflowRect() const { return m_layoutOverflow; }
     const LayoutRect visualOverflowRect() const { return m_visualOverflow; }
+    LayoutRect contentsVisualOverflowRect() const { return m_contentsVisualOverflow; }
 
     void setMinYLayoutOverflow(LayoutUnit overflow) { m_layoutOverflow.setY(overflow); }
     void setMaxYLayoutOverflow(LayoutUnit overflow) { m_layoutOverflow.setHeight(overflow - m_layoutOverflow.y()); }
     void setMinXLayoutOverflow(LayoutUnit overflow) { m_layoutOverflow.setX(overflow); }
     void setMaxXLayoutOverflow(LayoutUnit overflow) { m_layoutOverflow.setWidth(overflow - m_layoutOverflow.x()); }
 
     void setMinYVisualOverflow(LayoutUnit overflow) { m_visualOverflow.setY(overflow); }
     void setMaxYVisualOverflow(LayoutUnit overflow) { m_visualOverflow.setHeight(overflow - m_layoutOverflow.y()); }
     void setMinXVisualOverflow(LayoutUnit overflow) { m_visualOverflow.setX(overflow); }
     void setMaxXVisualOverflow(LayoutUnit overflow) { m_visualOverflow.setWidth(overflow - m_layoutOverflow.x()); }
 
     void move(LayoutUnit dx, LayoutUnit dy);
 
     void addLayoutOverflow(const LayoutRect&);
     void addVisualOverflow(const LayoutRect&);
+    void addContentsVisualOverflow(const LayoutRect& rect) { m_contentsVisualOverflow.unite(rect); }
 
     void setLayoutOverflow(const LayoutRect&);
     void setVisualOverflow(const LayoutRect&);
 
     LayoutUnit layoutClientAfterEdge() const { return m_layoutClientAfterEdge; }
     void setLayoutClientAfterEdge(LayoutUnit clientAfterEdge) { m_layoutClientAfterEdge = clientAfterEdge; }
 
 private:
     LayoutRect m_layoutOverflow;
     LayoutRect m_visualOverflow;
+    LayoutRect m_contentsVisualOverflow;
 
     LayoutUnit m_layoutClientAfterEdge;
 };
 
 inline void RenderOverflow::move(LayoutUnit dx, LayoutUnit dy)
 {
     m_layoutOverflow.move(dx, dy);
     m_visualOverflow.move(dx, dy);
+    m_contentsVisualOverflow.move(dx, dy);
 }
 
 inline void RenderOverflow::addLayoutOverflow(const LayoutRect& rect)
 {
     LayoutUnit maxX = std::max(rect.maxX(), m_layoutOverflow.maxX());
     LayoutUnit maxY = std::max(rect.maxY(), m_layoutOverflow.maxY());
     m_layoutOverflow.setX(std::min(rect.x(), m_layoutOverflow.x()));
     m_layoutOverflow.setY(std::min(rect.y(), m_layoutOverflow.y()));
     m_layoutOverflow.setWidth(maxX - m_layoutOverflow.x());
     m_layoutOverflow.setHeight(maxY - m_layoutOverflow.y());
@@ skipping 15 matching lines @@
 }
 
 inline void RenderOverflow::setVisualOverflow(const LayoutRect& rect)
 {
     m_visualOverflow = rect;
 }
 
 } // namespace WebCore
 
 #endif // RenderOverflow_h