Update should paint flag when a float's composited scrolling status changes

third_party/WebKit/Source/core/layout/LayoutBlockFlow.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2003-2013 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
@@ skipping 314 matching lines @@
 
     void removeFloatingObject(LayoutBox*);
     void removeFloatingObjectsBelow(FloatingObject*, int logicalOffset);
 
     LayoutUnit getClearDelta(LayoutBox* child, LayoutUnit yPos);
 
     bool hasOverhangingFloats() { return parent() && containsFloats() && lowestFloatLogicalBottom() > logicalHeight(); }
     bool hasOverhangingFloat(LayoutBox*);
     void addIntrudingFloats(LayoutBlockFlow* prev, LayoutUnit xoffset, LayoutUnit yoffset);
     void addOverhangingFloats(LayoutBlockFlow* child, bool makeChildPaintOtherFloats);
+    bool isOverhangingFloat(const FloatingObject& floatObject) const { return logicalBottomForFloat(floatObject) > logicalHeight(); }
 
     LayoutUnit lowestFloatLogicalBottom(FloatingObject::Type = FloatingObject::FloatLeftRight) const;
 
     bool hitTestFloats(HitTestResult&, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset) final;
 
     void invalidatePaintForOverhangingFloats(bool paintAllDescendants) final;
     void invalidatePaintForOverflow() final;
     void paintFloats(const PaintInfo&, const LayoutPoint&) const final;
     virtual void clipOutFloatingObjects(const LayoutBlock*, ClipScope&, const LayoutPoint&, const LayoutSize&) const;
     void clearFloats(EClear);
@@ skipping 124 matching lines @@
         LayoutMultiColumnFlowThread* m_multiColumnFlowThread;
 
         int m_lineBreakToAvoidWidow;
         bool m_didBreakAtLineToAvoidWidow : 1;
         bool m_discardMarginBefore : 1;
         bool m_discardMarginAfter : 1;
     };
 
     const FloatingObjects* floatingObjects() const { return m_floatingObjects.get(); }
 
+    static void setAncestorShouldPaintFloatingObject(const LayoutBox& floatBox, bool shouldPaint);
 
 protected:
     LayoutUnit maxPositiveMarginBefore() const { return m_rareData ? m_rareData->m_margins.positiveMarginBefore() : LayoutBlockFlowRareData::positiveMarginBeforeDefault(this); }
     LayoutUnit maxNegativeMarginBefore() const { return m_rareData ? m_rareData->m_margins.negativeMarginBefore() : LayoutBlockFlowRareData::negativeMarginBeforeDefault(this); }
     LayoutUnit maxPositiveMarginAfter() const { return m_rareData ? m_rareData->m_margins.positiveMarginAfter() : LayoutBlockFlowRareData::positiveMarginAfterDefault(this); }
     LayoutUnit maxNegativeMarginAfter() const { return m_rareData ? m_rareData->m_margins.negativeMarginAfter() : LayoutBlockFlowRareData::negativeMarginAfterDefault(this); }
 
     void setMaxMarginBeforeValues(LayoutUnit pos, LayoutUnit neg);
     void setMaxMarginAfterValues(LayoutUnit pos, LayoutUnit neg);
 
@@ skipping 98 matching lines @@
 
 // END METHODS DEFINED IN LayoutBlockFlowLine
 
 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutBlockFlow, isLayoutBlockFlow());
 
 } // namespace blink
 
 #endif // LayoutBlockFlow_h