Correct visual rects for scroll corner/resizer and non-frame composited scroll bars.

third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@gmail.com>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 1077 matching lines @@
 {
     if (!m_scrollCorner && !hasScrollbar())
         return;
     if (!m_scrollCorner && hasOverlayScrollbars())
         return;
 
     const LayoutObject& actualLayoutObject = layoutObjectForScrollbar(box());
     RefPtr<ComputedStyle> corner = box().hasOverflowClip() ? actualLayoutObject.getUncachedPseudoStyle(PseudoStyleRequest(PseudoIdScrollbarCorner), actualLayoutObject.style()) : PassRefPtr<ComputedStyle>(nullptr);
     if (corner) {
         if (!m_scrollCorner) {
-            m_scrollCorner = LayoutScrollbarPart::createAnonymous(&box().document());
+            m_scrollCorner = LayoutScrollbarPart::createAnonymous(&box().document(), this);
             m_scrollCorner->setDangerousOneWayParent(&box());
         }
         m_scrollCorner->setStyleWithWritingModeOfParent(corner.release());
     } else if (m_scrollCorner) {
         m_scrollCorner->destroy();
         m_scrollCorner = nullptr;
     }
 }
 
 bool PaintLayerScrollableArea::hitTestOverflowControls(HitTestResult& result, const IntPoint& localPoint)
@@ skipping 107 matching lines @@
 
 void PaintLayerScrollableArea::updateResizerStyle()
 {
     if (!m_resizer && !box().canResize())
         return;
 
     const LayoutObject& actualLayoutObject = layoutObjectForScrollbar(box());
     RefPtr<ComputedStyle> resizer = box().hasOverflowClip() ? actualLayoutObject.getUncachedPseudoStyle(PseudoStyleRequest(PseudoIdResizer), actualLayoutObject.style()) : PassRefPtr<ComputedStyle>(nullptr);
     if (resizer) {
         if (!m_resizer) {
-            m_resizer = LayoutScrollbarPart::createAnonymous(&box().document());
+            m_resizer = LayoutScrollbarPart::createAnonymous(&box().document(), this);
             m_resizer->setDangerousOneWayParent(&box());
         }
         m_resizer->setStyleWithWritingModeOfParent(resizer.release());
     } else if (m_resizer) {
         m_resizer->destroy();
         m_resizer = nullptr;
     }
 }
 
 IntSize PaintLayerScrollableArea::offsetFromResizeCorner(const IntPoint& absolutePoint) const
@@ skipping 347 matching lines @@
 }
 
 DEFINE_TRACE(PaintLayerScrollableArea::ScrollbarManager)
 {
     visitor->trace(m_scrollableArea);
     visitor->trace(m_hBar);
     visitor->trace(m_vBar);
 }
 
 } // namespace blink