Need to invalidate scrollbars in case they get repositioned.

Source/core/rendering/RenderBox.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2006, 2007 Apple 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
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 676 matching lines @@
     virtual void incrementallyInvalidatePaint(const LayoutLayerModelObject& paintInvalidationContainer, const LayoutRect& oldBounds, const LayoutRect& newBounds, const LayoutPoint& positionFromPaintInvalidationContainer) override;
 
     virtual void clearPaintInvalidationState(const PaintInvalidationState&) override;
 #if ENABLE(ASSERT)
     virtual bool paintInvalidationStateIsDirty() const override;
 #endif
 
     virtual PaintInvalidationReason invalidatePaintIfNeeded(const PaintInvalidationState&, const LayoutLayerModelObject& newPaintInvalidationContainer) override;
     virtual void invalidateDisplayItemClients(DisplayItemList*) const override;
 
+    virtual bool hasNonCompositedScrollbars() const final;

[dsinclair, 2015/02/23 15:13:53]

Should this be override instead of virtual?

[mstensho (USE GERRIT), 2015/02/23 17:22:38]

It's already a final override (there's a call site from RenderBox, so making it
final should save a few CPU cycles). Should I drop the "virtual" keyword, or
what did you mean? Everyone else around here repeat "virtual" on overrides, so I
thought it would look weird and special to omit it.

+
 private:
     void updateShapeOutsideInfoAfterStyleChange(const LayoutStyle&, const LayoutStyle* oldStyle);
     void updateGridPositionAfterStyleChange(const LayoutStyle*);
 
     bool autoWidthShouldFitContent() const;
     LayoutUnit shrinkToFitLogicalWidth(LayoutUnit availableLogicalWidth, LayoutUnit bordersPlusPadding) const;
 
     // Returns true if we queued up a paint invalidation.
     bool paintInvalidationLayerRectsForImage(WrappedImagePtr, const FillLayer&, bool drawingBackground);
 
@@ skipping 42 matching lines @@
     // The width/height of the contents + borders + padding.  The x/y location is relative to our container (which is not always our parent).
     LayoutRect m_frameRect;
 
     // Our intrinsic height, used for min-height: min-content etc. Maintained by
     // updateLogicalHeight. This is logicalHeight() before it is clamped to
     // min/max.
     mutable LayoutUnit m_intrinsicContentLogicalHeight;
 
     void inflatePaintInvalidationRectForReflectionAndFilter(LayoutRect&) const;
 
-    bool hasNonCompositedScrollbars() const;
-
     LayoutRectOutsets m_marginBoxOutsets;
 
 protected:
     // The preferred logical width of the element if it were to break its lines at every possible opportunity.
     LayoutUnit m_minPreferredLogicalWidth;
 
     // The preferred logical width of the element if it never breaks any lines at all.
     LayoutUnit m_maxPreferredLogicalWidth;
 
     // Our overflow information.
@@ skipping 72 matching lines @@
         if (UNLIKELY(inlineBoxWrapper() != 0))
             deleteLineBoxWrapper();
     }
 
     ensureRareData().m_inlineBoxWrapper = boxWrapper;
 }
 
 } // namespace blink
 
 #endif // RenderBox_h