Unified invalidation for repaint-only style change of layers

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 72 matching lines @@
 
     RenderObject::willBeDestroyed();
 
     destroyLayer();
 }
 
 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) {
-        // Do a repaint with the old style first through RenderLayerRepainter.
-        // RenderObject::styleWillChange takes care of repainting objects without RenderLayers.
+    if (RenderStyle* oldStyle = style()) {
         if (parent() && diff.needsRepaintLayer()) {
-            // This is currently need to make non-layout-requiring updates work that impact descendant layers,
-            // such as changes to opacity or transform.
-            layer()->repainter().repaintIncludingNonCompositingDescendants();
             if (oldStyle->hasClip() != newStyle.hasClip()
                 || oldStyle->clip() != newStyle.clip())
                 layer()->clipper().clearClipRectsIncludingDescendants();
         }
     }
 
     RenderObject::styleWillChange(diff, newStyle);
 }
 
 void RenderLayerModelObject::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
@@ skipping 95 matching lines @@
     InvalidationReason reason = invalidatePaintIfNeeded(paintInvalidationState, newPaintInvalidationContainer);
 
     PaintInvalidationState childTreeWalkState(paintInvalidationState, *this, newPaintInvalidationContainer);
     if (reason == InvalidationLocationChange || reason == InvalidationFull)
         childTreeWalkState.setForceCheckForPaintInvalidation();
     RenderObject::invalidateTreeIfNeeded(childTreeWalkState);
 }
 
 } // namespace blink