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 * Copyright (C) 2013 Google Inc. All rights reserved.
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 * modification, are permitted provided that the following conditions are
 * met:
 *
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 * notice, this list of conditions and the following disclaimer.
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 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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#ifndef SubtreeLayoutScope_h
#define SubtreeLayoutScope_h

#include "wtf/HashSet.h"

// This is the way to mark a subtree as needing layout during layout,
// e.g. for the purposes of doing a multipass layout.
//
// It should only be used during layout. Outside of layout, you should
// just call renderer->setNeedsLayout() directly.
//
// It ensures that you don't accidentally mark part of the tree as
// needing layout and not actually lay it out.

namespace WebCore {

class RenderObject;

class SubtreeLayoutScope {
public:
    SubtreeLayoutScope(RenderObject* root);
    ~SubtreeLayoutScope();

    void setNeedsLayout(RenderObject* descendant);
    void setChildNeedsLayout(RenderObject* descendant);

    RenderObject* root() { return m_root; }
    void addRendererToLayout(RenderObject* renderer);

private:
    RenderObject* m_root;

#ifndef NDEBUG
    HashSet<RenderObject*> m_renderersToLayout;
#endif
};

}

#endif