*** FOR PROTOTYPE PURPOSES ONLY! NOT INTENDED FOR COMMIT! ***

Source/core/rendering/RenderListItem.cpp

Index: Source/core/rendering/RenderListItem.cpp
diff --git a/Source/core/rendering/RenderListItem.cpp b/Source/core/rendering/RenderListItem.cpp
index 3b6b21cb02b08fd33e2504c331faf990cd082dff..2367f0a93058ddede84c670fc34aadfcf1f05fac 100644
--- a/Source/core/rendering/RenderListItem.cpp
+++ b/Source/core/rendering/RenderListItem.cpp
@@ -315,6 +315,16 @@ void RenderListItem::updateMarkerLocation()
 
 void RenderListItem::layout()
 {
+    internalLayout(true);
+}
+
+void RenderListItem::preLayout()
+{
+    internalLayout(false);
+}
+
+void RenderListItem::internalLayout(bool fullLayout)
+{
     ASSERT(needsLayout());
 
     // The marker must be autosized before calling updateMarkerLocation.
@@ -325,7 +335,15 @@ void RenderListItem::layout()
 
     LayoutRectRecorder recorder(*this);
     updateMarkerLocation();
-    RenderBlockFlow::layout();
+    if (fullLayout)
+        RenderBlockFlow::layout(); // this will traverse children...
+    else
+        RenderBlockFlow::preLayout();
+}
+
+void RenderListItem::postLayout()
+{
+    RenderBlockFlow::postLayout();
 }
 
 void RenderListItem::addOverflowFromChildren()