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

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

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. 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>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 2698 matching lines @@
     }
 }
 
 void PaintLayer::clearNeedsRepaintRecursively()
 {
     for (PaintLayer* child = firstChild(); child; child = child->nextSibling())
         child->clearNeedsRepaintRecursively();
     m_needsRepaint = false;
 }
 
+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";
+}
+
+DisplayItemClientWrapper PaintLayer::displayItemClientForNegativeZOrderChildren() const
+{
+    return DisplayItemClientWrapper(*this, toSubDisplayItemClient(this, 1), debugNameForNegativeZOrderChildrenDisplayItemClient);
+}
+
+DisplayItemClientWrapper PaintLayer::displayItemClientForNormalAndPositiveZOrderChildren() const
+{
+    return DisplayItemClientWrapper(*this, toSubDisplayItemClient(this, 2), debugNameForNormalAndPositiveZOrderChildrenDisplayItemClient);
+}
+
 DisableCompositingQueryAsserts::DisableCompositingQueryAsserts()
     : m_disabler(gCompositingQueryMode, CompositingQueriesAreAllowed) { }
 
 } // namespace blink
 
 #ifndef NDEBUG
 // FIXME: Rename?
 void showLayerTree(const blink::PaintLayer* layer)
 {
     if (!layer) {
         fprintf(stderr, "Cannot showLayerTree. Root is (nil)\n");
         return;
     }
 
     if (blink::LocalFrame* frame = layer->layoutObject()->frame()) {
         WTF::String output = externalRepresentation(frame, blink::LayoutAsTextShowAllLayers | blink::LayoutAsTextShowLayerNesting | blink::LayoutAsTextShowCompositedLayers | blink::LayoutAsTextShowAddresses | blink::LayoutAsTextShowIDAndClass | blink::LayoutAsTextDontUpdateLayout | blink::LayoutAsTextShowLayoutState);
         fprintf(stderr, "%s\n", output.utf8().data());
     }
 }
 
 void showLayerTree(const blink::LayoutObject* layoutObject)
 {
     if (!layoutObject) {
         fprintf(stderr, "Cannot showLayerTree. Root is (nil)\n");
         return;
     }
     showLayerTree(layoutObject->enclosingLayer());
 }
 #endif