Walk render tree instead of render layers for paint.

sky/engine/core/rendering/RenderView.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2006 Apple Computer, Inc.
  *
  * 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,
@@ skipping 50 matching lines @@
 
     // The same as the FrameView's layoutHeight/layoutWidth but with null check guards.
     int viewHeight() const;
     int viewWidth() const;
     int viewLogicalWidth() const { return viewWidth(); }
     int viewLogicalHeight() const;
     LayoutUnit viewLogicalHeightForPercentages() const;
 
     FrameView* frameView() const { return m_frameView; }
 
-    virtual void paint(PaintInfo&, const LayoutPoint&) override;
+    virtual void paint(PaintInfo&, const LayoutPoint&, Vector<RenderBox*>& layers) override;
     virtual void paintBoxDecorationBackground(PaintInfo&, const LayoutPoint&) override;
 
     void setSelection(RenderObject* start, int startPos, RenderObject*, int endPos);
     void getSelection(RenderObject*& startRenderer, int& startOffset, RenderObject*& endRenderer, int& endOffset) const;
     void clearSelection();
     RenderObject* selectionStart() const { return m_selectionStart; }
     RenderObject* selectionEnd() const { return m_selectionEnd; }
     void selectionStartEnd(int& startPos, int& endPos) const;
 
     virtual void absoluteQuads(Vector<FloatQuad>&) const override;
@@ skipping 52 matching lines @@
     unsigned m_hitTestCount;
 
     WTF::HashSet<RenderIFrame*> m_iframes;
 };
 
 DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderView, isRenderView());
 
 } // namespace blink
 
 #endif  // SKY_ENGINE_CORE_RENDERING_RENDERVIEW_H_