Remove logic forcing paint invalidation with non-composited scrollbars

third_party/WebKit/Source/core/paint/BoxPaintInvalidator.cpp

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/paint/BoxPaintInvalidator.h"
 
 #include "core/frame/Settings.h"
 #include "core/layout/LayoutView.h"
 #include "core/paint/ObjectPaintInvalidator.h"
 #include "core/paint/PaintInvalidator.h"
@@ skipping 164 matching lines @@
   if (m_context.oldVisualRect !=
           LayoutRect(m_context.oldLocation, oldBorderBoxSize) ||
       m_context.newVisualRect !=
           LayoutRect(m_context.newLocation, newBorderBoxSize)) {
     return borderBoxChanged ? PaintInvalidationBorderBoxChange
                             : PaintInvalidationBoundsChange;
   }
 
   DCHECK(borderBoxChanged);
 
-  if (m_box.hasNonCompositedScrollbars())
-    return PaintInvalidationBorderBoxChange;
-
   if (style.hasVisualOverflowingEffect() || style.hasAppearance() ||
       style.hasFilterInducingProperty() || style.resize() != RESIZE_NONE ||
       style.hasMask())
     return PaintInvalidationBorderBoxChange;
 
   if (style.hasBorderRadius())
     return PaintInvalidationBorderBoxChange;
 
   if (oldBorderBoxSize.width() != newBorderBoxSize.width() &&
       m_box.mustInvalidateBackgroundOrBorderPaintOnWidthChange())
@@ skipping 106 matching lines @@
 
 LayoutRect BoxPaintInvalidator::previousLayoutOverflowRect() {
   DCHECK(m_box.hasPreviousBoxGeometries() ==
          previousBoxGeometriesMap().contains(&m_box));
   return m_box.hasPreviousBoxGeometries()
              ? previousBoxGeometriesMap().get(&m_box).layoutOverflowRect
              : LayoutRect();
 }
 
 }  // namespace blink