[New Multicolumn] Layout support for column-span:all.

Source/core/rendering/RenderLayer.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 800 matching lines @@
         RenderInline* inlineFlow = toRenderInline(renderer());
         IntRect lineBox = inlineFlow->linesBoundingBox();
         m_size = lineBox.size();
         inlineBoundingBoxOffset = lineBox.location();
         localPoint.moveBy(inlineBoundingBoxOffset);
     } else if (RenderBox* box = renderBox()) {
         m_size = pixelSnappedIntSize(box->size(), box->location());
         localPoint.moveBy(box->topLeftLocation());
     }
 
-    if (!renderer()->isOutOfFlowPositioned() && renderer()->parent()) {
+    if (!renderer()->isOutOfFlowPositioned() && !renderer()->isColumnSpanAll() && renderer()->parent()) {
         // We must adjust our position by walking up the render tree looking for the
         // nearest enclosing object with a layer.
         RenderObject* curr = renderer()->parent();
         while (curr && !curr->hasLayer()) {
             if (curr->isBox() && !curr->isTableRow()) {
                 // Rows and cells share the same coordinate space (that of the section).
                 // Omit them when computing our xpos/ypos.
                 localPoint.moveBy(toRenderBox(curr)->topLeftLocation());
             }
             curr = curr->parent();
@@ skipping 588 matching lines @@
 
             LayoutPoint thisCoords;
             layer->convertToLayerCoords(positionedAncestor, thisCoords);
 
             LayoutPoint ancestorCoords;
             ancestorLayer->convertToLayerCoords(positionedAncestor, ancestorCoords);
 
             location += (thisCoords - ancestorCoords);
             return ancestorLayer;
         }
-    } else
+    } else if (renderer->isColumnSpanAll()) {
+        RenderBlock* multicolContainer = renderer->containingBlock();
+        ASSERT(toRenderBlockFlow(multicolContainer)->multiColumnFlowThread());
+        parentLayer = multicolContainer->layer();
+        ASSERT(parentLayer);
+    } else {
         parentLayer = layer->parent();
+    }
 
     if (!parentLayer)
         return 0;
 
     location += layer->location();
     return parentLayer;
 }
 
 void RenderLayer::convertToLayerCoords(const RenderLayer* ancestorLayer, LayoutPoint& location) const
 {
@@ skipping 1433 matching lines @@
     }
 }
 
 void showLayerTree(const blink::RenderObject* renderer)
 {
     if (!renderer)
         return;
     showLayerTree(renderer->enclosingLayer());
 }
 #endif