Separate display item clients for negative and normal/positive z-order children

third_party/WebKit/Source/core/paint/PaintLayer.h

 /*
  * Copyright (C) 2003, 2009, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Intel Corporation. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
@@ skipping 598 matching lines @@
     static LayoutRect transparencyClipBox(const PaintLayer*, const PaintLayer* rootLayer, TransparencyClipBoxBehavior transparencyBehavior,
         TransparencyClipBoxMode transparencyMode, const LayoutSize& subPixelAccumulation, GlobalPaintFlags = GlobalPaintNormalPhase);
 
     bool needsRepaint() const { return m_needsRepaint; }
     void setNeedsRepaint();
     void clearNeedsRepaintRecursively();
 
     IntSize previousScrollOffsetAccumulationForPainting() const { return m_previousScrollOffsetAccumulationForPainting; }
     void setPreviousScrollOffsetAccumulationForPainting(const IntSize& s) { m_previousScrollOffsetAccumulationForPainting = s; }
 
-    // For subsequence display items.
-    DisplayItemClient displayItemClient() const { return toDisplayItemClient(this); }
+    DisplayItemClientWrapper displayItemClientForNegativeZOrderChildren() const;
+    DisplayItemClientWrapper displayItemClientForNormalAndPositiveZOrderChildren() const;
+
+    static String debugNameForNegativeZOrderChildrenDisplayItemClient(const PaintLayer& layer) { return layer.debugName() + " negative z-order children"; }
+    static String debugNameForNormalAndPositiveZOrderChildrenDisplayItemClient(const PaintLayer& layer) { return layer.debugName() + " normal and positive z-order children"; }
 
 private:
     // Bounding box in the coordinates of this layer.
     LayoutRect logicalBoundingBox() const;
 
     bool hasOverflowControls() const;
 
     void dirtyAncestorChainHasSelfPaintingLayerDescendantStatus();
 
     // Returns true if the position changed.
@@ skipping 179 matching lines @@
 
 } // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showLayerTree(const blink::PaintLayer*);
 void showLayerTree(const blink::LayoutObject*);
 #endif
 
 #endif // Layer_h