Replace LayoutObject::skipInvalidationWhenLaidOutChildren() with paintedOutputOfObjectHasNoEffect

third_party/WebKit/Source/core/layout/LayoutBox.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, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. 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 2016 matching lines @@
 {
     ASSERT(isBreakBetweenControllable(previousBreakAfterValue));
     return joinFragmentainerBreakValues(previousBreakAfterValue, breakBefore());
 }
 
 bool LayoutBox::needsForcedBreakBefore(EBreak previousBreakAfterValue) const
 {
     return isForcedFragmentainerBreakValue(classABreakPointValue(previousBreakAfterValue));
 }
 
+bool LayoutBox::paintedOutputOfObjectHasNoEffect() const
+{
+    // In case scrollbars got repositioned (which will typically happen if the box got
+    // resized), we cannot skip invalidation.
+    if (hasNonCompositedScrollbars())
+        return false;
+
+    // Cannot skip paint invalidation if the box has real things to paint.
+    if (getSelectionState() != SelectionNone || hasBoxDecorationBackground() || styleRef().hasVisualOverflowingEffect())
+        return false;
+
+    // If the box has clip, we need issue a paint invalidation to cover the changed part of
+    // children because of change of clip when the box got resized. In theory the children
+    // should invalidate themselves when ancestor clip changes, but for now this is missing
+    // and ensuring it may hurt performance.
+    // TODO(wangxianzhu): Paint invalidation for clip change will be different in spv2.
+    if (hasClipRelatedProperty() || hasControlClip())
+        return false;
+
+    return true;
+}
+
 LayoutRect LayoutBox::localOverflowRectForPaintInvalidation() const
 {
     if (style()->visibility() != VISIBLE)
         return LayoutRect();
 
     return selfVisualOverflowRect();
 }
 
 void LayoutBox::inflateVisualRectForReflectionAndFilterUnderContainer(LayoutRect& rect, const LayoutObject& container, const LayoutBoxModelObject* ancestorToStopAt) const
 {
@@ skipping 2918 matching lines @@
         m_rareData->m_snapAreas->remove(&snapArea);
     }
 }
 
 SnapAreaSet* LayoutBox::snapAreas() const
 {
     return m_rareData ? m_rareData->m_snapAreas.get() : nullptr;
 }
 
 } // namespace blink