Separate repaint and layout requirements of StyleDifference (Step 3)

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 85 matching lines @@
     // we need to dirty our stacking context's z-order list.
     RenderStyle* oldStyle = style();
     if (oldStyle) {
         // Do a repaint with the old style first through RenderLayerRepainter.
         // RenderObject::styleWillChange takes care of repainting objects without RenderLayers.
         if (parent() && diff.needsRepaintLayer()) {
             layer()->repainter().repaintIncludingNonCompositingDescendants(containerForRepaint());
             if (oldStyle->hasClip() != newStyle.hasClip()
                 || oldStyle->clip() != newStyle.clip())
                 layer()->clipper().clearClipRectsIncludingDescendants();
-        }
-
-        if (diff.needsFullLayout()) {
-            // When a layout hint happens, we go ahead and do a repaint of the layer, since the layer could
-            // end up being destroyed.
+        } else if (diff.needsFullLayout()) {
             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.
+                if (!layer()->hasCompositedLayerMapping() && oldStyle->position() != newStyle.position())
                     layer()->repainter().repaintIncludingNonCompositingDescendants(containerForRepaint());
-                } else if (!layer()->hasCompositedLayerMapping()) {
-                    if (oldStyle->position() != newStyle.position()
-                        || oldStyle->zIndex() != newStyle.zIndex()
-                        || oldStyle->hasAutoZIndex() != newStyle.hasAutoZIndex()
-                        || oldStyle->opacity() != newStyle.opacity()
-                        || oldStyle->transform() != newStyle.transform()
-                        || oldStyle->filter() != newStyle.filter())
-                        layer()->repainter().repaintIncludingNonCompositingDescendants(containerForRepaint());
-                }
             } else if (newStyle.hasTransform() || newStyle.opacity() < 1 || newStyle.hasFilter()) {
                 // If we don't have a layer yet, but we are going to get one because of transform or opacity,
                 //  then we need to repaint the old position of the object.
                 repaint();
             }
         }
     }
 
     RenderObject::styleWillChange(diff, newStyle);
 }
@@ skipping 87 matching lines @@
     return m_layer ? m_layer->hasCompositedLayerMapping() : false;
 }
 
 CompositedLayerMapping* RenderLayerModelObject::groupedMapping() const
 {
     return m_layer ? m_layer->groupedMapping() : 0;
 }
 
 } // namespace WebCore