Fix re-layout logic in LayoutScrollbar::updateScrollbarParts.

Source/core/layout/LayoutScrollbar.cpp

 /*
  * Copyright (C) 2008, 2009 Apple Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 14 matching lines @@
 
 #include "config.h"
 #include "core/layout/LayoutScrollbar.h"
 
 #include "core/css/PseudoStyleRequest.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/layout/LayoutPart.h"
 #include "core/layout/LayoutScrollbarPart.h"
 #include "core/layout/LayoutScrollbarTheme.h"
+#include "core/layout/LayoutView.h"
 #include "platform/graphics/GraphicsContext.h"
 
 namespace blink {
 
 PassRefPtrWillBeRawPtr<Scrollbar> LayoutScrollbar::createCustomScrollbar(ScrollableArea* scrollableArea, ScrollbarOrientation orientation, Node* ownerNode, LocalFrame* owningFrame)
 {
     return adoptRefWillBeNoop(new LayoutScrollbar(scrollableArea, orientation, ownerNode, owningFrame));
 }
 
 LayoutScrollbar::LayoutScrollbar(ScrollableArea* scrollableArea, ScrollbarOrientation orientation, Node* ownerNode, LocalFrame* owningFrame)
@@ skipping 44 matching lines @@
     Scrollbar::trace(visitor);
 }
 
 LayoutBox* LayoutScrollbar::owningLayoutObject() const
 {
     if (m_owningFrame)
         return m_owningFrame->ownerLayoutObject();
     return m_owner && m_owner->layoutObject() ? m_owner->layoutObject()->enclosingBox() : 0;
 }
 
+LayoutBox* LayoutScrollbar::owningLayoutObjectWithinFrame() const
+{
+    if (m_owningFrame)
+        return m_owningFrame->contentLayoutObject();
+    return owningLayoutObject();
+}
+
 void LayoutScrollbar::setParent(Widget* parent)
 {
     Scrollbar::setParent(parent);
     if (!parent) {
         // Destroy all of the scrollbar's LayoutBoxes.
         updateScrollbarParts(true);
     }
 }
 
 void LayoutScrollbar::setEnabled(bool e)
@@ skipping 72 matching lines @@
     int oldThickness = isHorizontal ? height() : width();
     int newThickness = 0;
     LayoutScrollbarPart* part = m_parts.get(ScrollbarBGPart);
     if (part) {
         part->layout();
         newThickness = isHorizontal ? part->size().height() : part->size().width();
     }
 
     if (newThickness != oldThickness) {
         setFrameRect(IntRect(location(), IntSize(isHorizontal ? width() : newThickness, isHorizontal ? newThickness : height())));
-        if (LayoutBox* box = owningLayoutObject()) {
+        if (LayoutBox* box = owningLayoutObjectWithinFrame()) {
             if (box->isLayoutBlock())
                 toLayoutBlock(box)->notifyScrollbarThicknessChanged();
             box->setChildNeedsLayout();
             if (RuntimeEnabledFeatures::slimmingPaintEnabled() && m_scrollableArea)
                 m_scrollableArea->invalidateScrollCorner(m_scrollableArea->scrollCornerRect());
         }
     }
 }
 
 static PseudoId pseudoForScrollbarPart(ScrollbarPart part)
@@ skipping 160 matching lines @@
         return;
 
     // FIXME: invalidate only the changed part.
     if (LayoutBox* owningLayoutObject = this->owningLayoutObject()) {
         for (auto& part : m_parts)
             owningLayoutObject->invalidateDisplayItemClientForNonCompositingDescendantsOf(*part.value);
     }
 }
 
 }