Remove duplicated invalidation

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 78 matching lines @@
 }
 
 void RenderLayerModelObject::styleWillChange(StyleDifference diff, const RenderStyle& newStyle)
 {
     s_wasFloating = isFloating();
 
     // If our z-index changes value or our visibility changes,
     // we need to dirty our stacking context's z-order list.
     RenderStyle* oldStyle = style();
     if (oldStyle) {
-        if (parent()) {
-            // Do a repaint with the old style first, e.g., for example if we go from
-            // having an outline to not having an outline.
-            if (diff == StyleDifferenceRepaintLayer) {
-                layer()->repainter().repaintIncludingDescendants();
-                if (oldStyle->clip() != newStyle.clip())
-                    layer()->clipper().clearClipRectsIncludingDescendants();
-            } else if (diff == StyleDifferenceRepaint || newStyle.outlineSize() < oldStyle->outlineSize())
-                repaint();
+        // Do a repaint with the old style first through RenderLayerRepainter.
+        // RenderObject::styleWillChange takes care of repainting objects without RenderLayers.
+        if (parent() && diff == StyleDifferenceRepaintLayer) {
+            layer()->repainter().repaintIncludingDescendants();
+            if (oldStyle->clip() != newStyle.clip())
+                layer()->clipper().clearClipRectsIncludingDescendants();
         }
 
         if (diff == StyleDifferenceLayout || diff == StyleDifferenceSimplifiedLayout) {
             // When a layout hint happens, we go ahead and do a repaint of the layer, since the layer could
             // end up being destroyed.
             if (hasLayer()) {
                 if (oldStyle->hasClip() != newStyle.hasClip()
                     || oldStyle->clip() != newStyle.clip()) {
                     // Composited layers don't need to be repainted when a parent's clip changes.
                     layer()->repainter().repaintIncludingNonCompositingDescendants(containerForRepaint());
@@ skipping 104 matching lines @@
     return m_layer ? m_layer->hasCompositedLayerMapping() : false;
 }
 
 CompositedLayerMapping* RenderLayerModelObject::groupedMapping() const
 {
     return m_layer ? m_layer->groupedMapping() : 0;
 }
 
 } // namespace WebCore