RLSA needsLayout on customscrollbar thickness change.

Source/core/rendering/RenderBlock.cpp

 /*
  * 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, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2010. 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
@@ skipping 134 matching lines @@
     bool m_hadHorizontalLayoutOverflow;
     bool m_hadVerticalLayoutOverflow;
 };
 
 RenderBlock::RenderBlock(ContainerNode* node)
     : RenderBox(node)
     , m_hasMarginBeforeQuirk(false)
     , m_hasMarginAfterQuirk(false)
     , m_beingDestroyed(false)
     , m_hasMarkupTruncation(false)
-    , m_hasBorderOrPaddingLogicalWidthChanged(false)
+    , m_widthAvailableToChildrenChanged(false)
     , m_hasOnlySelfCollapsingChildren(false)
     , m_descendantsWithFloatsMarkedForLayout(false)
 {
     // RenderBlockFlow calls setChildrenInline(true).
     // By default, subclasses do not have inline children.
 }
 
 void RenderBlock::trace(Visitor* visitor)
 {
     visitor->trace(m_children);
@@ skipping 194 matching lines @@
         }
     }
 
     if (TextAutosizer* textAutosizer = document().textAutosizer())
         textAutosizer->record(this);
 
     propagateStyleToAnonymousChildren(true);
 
     // It's possible for our border/padding to change, but for the overall logical width of the block to
     // end up being the same. We keep track of this change so in layoutBlock, we can know to set relayoutChildren=true.
-    m_hasBorderOrPaddingLogicalWidthChanged = oldStyle && diff.needsFullLayout() && needsLayout() && borderOrPaddingLogicalWidthChanged(oldStyle, newStyle);
+    m_widthAvailableToChildrenChanged = oldStyle && diff.needsFullLayout() && needsLayout() && borderOrPaddingLogicalWidthChanged(oldStyle, newStyle);
+
+    // Include CustomScrollbars to calculate width available to children changed.
+    m_widthAvailableToChildrenChanged |= needsLayout() && customScrollbarThicknessChanged();
 
     // If the style has unloaded images, want to notify the ResourceLoadPriorityOptimizer so that
     // network priorities can be set.
     Vector<ImageResource*> images;
     appendImagesFromStyle(images, *newStyle);
     if (images.isEmpty())
         ResourceLoadPriorityOptimizer::resourceLoadPriorityOptimizer()->removeRenderObject(this);
     else
         ResourceLoadPriorityOptimizer::resourceLoadPriorityOptimizer()->addRenderObject(this);
 }
@@ skipping 1046 matching lines @@
     }
 
     for (Vector<ImageResource*>::iterator it = images.begin(), end = images.end(); it != end; ++it)
         ResourceLoadPriorityOptimizer::resourceLoadPriorityOptimizer()->notifyImageResourceVisibility(*it, status, screenArea);
 
     return true;
 }
 
 bool RenderBlock::widthAvailableToChildrenHasChanged()
 {
-    bool widthAvailableToChildrenHasChanged = m_hasBorderOrPaddingLogicalWidthChanged;
-    m_hasBorderOrPaddingLogicalWidthChanged = false;
+    bool widthAvailableToChildrenHasChanged = m_widthAvailableToChildrenChanged;
+    m_widthAvailableToChildrenChanged = false;
+    setCustomScrollbarThicknessChanged(false);
 
     // If we use border-box sizing, have percentage padding, and our parent has changed width then the width available to our children has changed even
     // though our own width has remained the same.
     widthAvailableToChildrenHasChanged |= style()->boxSizing() == BORDER_BOX && needsPreferredWidthsRecalculation() && view()->layoutState()->containingBlockLogicalWidthChanged();
 
     return widthAvailableToChildrenHasChanged;
 }
 
 bool RenderBlock::updateLogicalWidthAndColumnWidth()
 {
@@ skipping 2961 matching lines @@
 void RenderBlock::showLineTreeAndMark(const InlineBox* markedBox1, const char* markedLabel1, const InlineBox* markedBox2, const char* markedLabel2, const RenderObject* obj) const
 {
     showRenderObject();
     for (const RootInlineBox* root = firstRootBox(); root; root = root->nextRootBox())
         root->showLineTreeAndMark(markedBox1, markedLabel1, markedBox2, markedLabel2, obj, 1);
 }
 
 #endif
 
 } // namespace blink