Revert of Invalidate scrolling contents on scrolling contents layer only

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 395 matching lines @@
 {
     if (layer()->groupedMapping()) {
         if (GraphicsLayer* squashingLayer = layer()->groupedMapping()->squashingLayer()) {
             // Note: the subpixel accumulation of layer() does not need to be added here. It is already taken into account.
             IntRect paintInvalidationRectOnSquashingLayer;
             if (paintInvalidationRect)
                 paintInvalidationRectOnSquashingLayer = enclosingIntRect(*paintInvalidationRect);
             squashingLayer->invalidateDisplayItemClient(displayItemClient, invalidationReason, paintInvalidationRect ? &paintInvalidationRectOnSquashingLayer : nullptr);
         }
     } else if (CompositedLayerMapping* compositedLayerMapping = layer()->compositedLayerMapping()) {
-        if (this != &displayItemClient && isBox() && toLayoutBox(this)->usesCompositedScrolling()) {
-            // This paint invalidation container is using composited scrolling, and we are invalidating a scrolling content,
-            // so we should invalidate on the scrolling contents layer only.
-            compositedLayerMapping->invalidateDisplayItemClientOnScrollingContentsLayer(displayItemClient, invalidationReason, paintInvalidationRect);
-        } else {
-            compositedLayerMapping->invalidateDisplayItemClient(displayItemClient, invalidationReason, paintInvalidationRect);
-        }
+        compositedLayerMapping->invalidateDisplayItemClient(displayItemClient, invalidationReason, paintInvalidationRect);
     }
 }
 
 void LayoutBoxModelObject::addOutlineRectsForNormalChildren(Vector<LayoutRect>& rects, const LayoutPoint& additionalOffset, IncludeBlockVisualOverflowOrNot includeBlockOverflows) const
 {
     for (LayoutObject* child = slowFirstChild(); child; child = child->nextSibling()) {
         // Outlines of out-of-flow positioned descendants are handled in LayoutBlock::addOutlineRects().
         if (child->isOutOfFlowPositioned())
             continue;
 
@@ skipping 638 matching lines @@
     if (rootElementStyle->hasBackground())
         return false;
 
     if (node() != document().firstBodyElement())
         return false;
 
     return true;
 }
 
 } // namespace blink