Invalidate non-self-painting-layer descendants when creating a layer

third_party/WebKit/Source/core/layout/LayoutBoxModelObject.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 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 262 matching lines @@
             if (newStyleIsViewportConstained && layer())
                 frameView->addViewportConstrainedObject(this);
             else
                 frameView->removeViewportConstrainedObject(this);
         }
     }
 }
 
 void LayoutBoxModelObject::createLayer(PaintLayerType type)
 {
-
-    // Acquiring a PaintLayer may change the paint invalidation container. Therefore we must eagerly
-    // invalidate paint for this object before creating the layer.
-    if (!RuntimeEnabledFeatures::slimmingPaintV2Enabled() && isRooted()) {
-        DisablePaintInvalidationStateAsserts invalidationDisabler;
-        DisableCompositingQueryAsserts compositingDisabler;
-
-        // It would be more correct to call invalidatePaintIncludingNonCompositingDescendants, but
-        // we do this instead to avoid performance issues when creating large numbers of layers.
-        const LayoutBoxModelObject& paintInvalidationContainer = containerForPaintInvalidationOnRootedTree();
-        invalidatePaintUsingContainer(
-            paintInvalidationContainer,
-            boundsRectForPaintInvalidation(&paintInvalidationContainer),
-            PaintInvalidationLayer);
+    // If the current paint invalidation container is not a stacking context and this object is
+    // a or treated as a stacking context, creating this layer may cause this object and its
+    // descendants to change paint invalidation container. Therefore we must eagerly invalidate
+    // them on the original paint invalidation container before creating the layer.
+    if (!RuntimeEnabledFeatures::slimmingPaintV2Enabled() && isRooted() && styleRef().isTreatedAsOrStackingContext()) {
+        if (const LayoutBoxModelObject* currentPaintInvalidationContainer = containerForPaintInvalidation()) {
+            if (!currentPaintInvalidationContainer->styleRef().isStackingContext())
+                invalidatePaintIncludingNonSelfPaintingLayerDescendants(*currentPaintInvalidationContainer);
+        }
     }
 
     ASSERT(!m_layer);
     m_layer = adoptPtr(new PaintLayer(this, type));
     setHasLayer(true);
     m_layer->insertOnlyThisLayer();
 }
 
 void LayoutBoxModelObject::destroyLayer()
 {
@@ skipping 748 matching lines @@
     if (rootElementStyle->hasBackground())
         return false;
 
     if (node() != document().firstBodyElement())
         return false;
 
     return true;
 }
 
 } // namespace blink