Cleanup: Remove LayoutRegion.

Source/core/paint/DeprecatedPaintLayer.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 1341 matching lines @@
 static inline const DeprecatedPaintLayer* accumulateOffsetTowardsAncestor(const DeprecatedPaintLayer* layer, const DeprecatedPaintLayer* ancestorLayer, LayoutPoint& location)
 {
     ASSERT(ancestorLayer != layer);
 
     const LayoutBoxModelObject* layoutObject = layer->layoutObject();
     EPosition position = layoutObject->style()->position();
 
     // FIXME: Positioning of out-of-flow(fixed, absolute) elements collected in a LayoutFlowThread
     // may need to be revisited in a future patch.
     // If the fixed layoutObject is inside a LayoutFlowThread, we should not compute location using localToAbsolute,
-    // since localToAbsolute maps the coordinates from flow thread to regions coordinates and regions can be
+    // since localToAbsolute maps the coordinates from flow thread to column set coordinates and column sets can be
     // positioned in a completely different place in the viewport (LayoutView).
     if (position == FixedPosition && (!ancestorLayer || ancestorLayer == layoutObject->view()->layer())) {
         // If the fixed layer's container is the root, just add in the offset of the view. We can obtain this by calling
         // localToAbsolute() on the LayoutView.
         FloatPoint absPos = layoutObject->localToAbsolute(FloatPoint(), IsFixed);
         location += LayoutSize(absPos.x(), absPos.y());
         return ancestorLayer;
     }
 
     // For the fixed positioned elements inside a layout flow thread, we should also skip the code path below
@@ skipping 1604 matching lines @@
     }
 }
 
 void showLayerTree(const blink::LayoutObject* layoutObject)
 {
     if (!layoutObject)
         return;
     showLayerTree(layoutObject->enclosingLayer());
 }
 #endif