Start removing the double-negative !ASSERT_DISABLED

Source/core/rendering/compositing/GraphicsLayerTreeBuilder.cpp

 /*
  * Copyright (C) 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2014 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 53 matching lines @@
     layer.stackingNode()->updateLayerListsIfNeeded();
 
     const bool hasCompositedLayerMapping = layer.hasCompositedLayerMapping();
     CompositedLayerMappingPtr currentCompositedLayerMapping = layer.compositedLayerMapping();
 
     // If this layer has a compositedLayerMapping, then that is where we place subsequent children GraphicsLayers.
     // Otherwise children continue to append to the child list of the enclosing layer.
     GraphicsLayerVector layerChildren;
     GraphicsLayerVector& childList = hasCompositedLayerMapping ? layerChildren : childLayersOfEnclosingLayer;
 
-#if !ASSERT_DISABLED
+#if ASSERT_ENABLED
     LayerListMutationDetector mutationChecker(layer.stackingNode());
 #endif
 
     if (layer.stackingNode()->isStackingContext()) {
         RenderLayerStackingNodeIterator iterator(*layer.stackingNode(), NegativeZOrderChildren);
         while (RenderLayerStackingNode* curNode = iterator.next())
             rebuild(*curNode->layer(), childList);
 
         // If a negative z-order child is compositing, we get a foreground layer which needs to get parented.
         if (hasCompositedLayerMapping && currentCompositedLayerMapping->foregroundLayer())
@@ skipping 30 matching lines @@
                 currentCompositedLayerMapping->parentForSublayers()->addChild(overflowControlLayer);
             }
         }
 
         if (shouldAppendLayer(layer))
             childLayersOfEnclosingLayer.append(currentCompositedLayerMapping->childForSuperlayers());
     }
 }
 
 }