Replace check for RenderLayer in RenderLayerModelObject::ensureLayer with ASSERT due to redundant c…

Source/core/rendering/RenderLayerModelObject.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2010, 2012 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 41 matching lines @@
 }
 
 void RenderLayerModelObject::destroyLayer()
 {
     ASSERT(!hasLayer()); // Callers should have already called setHasLayer(false)
     ASSERT(m_layer);
     delete m_layer;
     m_layer = 0;
 }
 
-void RenderLayerModelObject::ensureLayer()
+void RenderLayerModelObject::createLayer()
 {
-    if (m_layer)
-        return;
-
+    ASSERT(!m_layer);
     m_layer = new RenderLayer(this);
     setHasLayer(true);
     m_layer->insertOnlyThisLayer();
 }
 
 bool RenderLayerModelObject::hasSelfPaintingLayer() const
 {
     return m_layer && m_layer->isSelfPaintingLayer();
 }
 
@@ skipping 68 matching lines @@
 
 void RenderLayerModelObject::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
 {
     RenderObject::styleDidChange(diff, oldStyle);
     updateFromStyle();
 
     if (requiresLayer()) {
         if (!layer() && layerCreationAllowedForSubtree()) {
             if (s_wasFloating && isFloating())
                 setChildNeedsLayout();
-            ensureLayer();
+            createLayer();
             if (parent() && !needsLayout() && containingBlock()) {
                 layer()->repainter().setRepaintStatus(NeedsFullRepaint);
                 // There is only one layer to update, it is not worth using |cachedOffset| since
                 // we are not sure the value will be used.
                 layer()->updateLayerPositions(0);
             }
         }
     } else if (layer() && layer()->parent()) {
         setHasTransform(false); // Either a transform wasn't specified or the object doesn't support transforms, so just null out the bit.
         setHasReflection(false);
@@ skipping 40 matching lines @@
     }
 }
 
 CompositedLayerMapping* RenderLayerModelObject::compositedLayerMapping() const
 {
     return m_layer ? m_layer->compositedLayerMapping() : 0;
 }
 
 } // namespace WebCore