rebase https://codereview.chromium.org/1484163002

third_party/WebKit/Source/core/frame/FrameView.cpp

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999 Lars Knoll <knoll@kde.org>
  *                     1999 Antti Koivisto <koivisto@kde.org>
  *                     2000 Dirk Mueller <mueller@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *           (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
@@ skipping 2312 matching lines @@
 
         if (!cornerStyle) {
             // If we have an owning ipage/LocalFrame element, then it can set the custom scrollbar also.
             if (LayoutPart* layoutObject = m_frame->ownerLayoutObject())
                 cornerStyle = layoutObject->getUncachedPseudoStyle(PseudoStyleRequest(PseudoIdScrollbarCorner), layoutObject->style());
         }
     }
 
     if (cornerStyle) {
         if (!m_scrollCorner)
-            m_scrollCorner = LayoutScrollbarPart::createAnonymous(doc);
+            m_scrollCorner = LayoutScrollbarPart::createAnonymous(doc, this);
         m_scrollCorner->setStyleWithWritingModeOfParent(cornerStyle.release());
         setScrollCornerNeedsPaintInvalidation();
     } else if (m_scrollCorner) {
         m_scrollCorner->destroy();
         m_scrollCorner = nullptr;
     }
 }
 
 Color FrameView::documentBackgroundColor() const
 {
@@ skipping 1748 matching lines @@
     return m_hiddenForThrottling && m_crossOriginForThrottling;
 }
 
 LayoutBox& FrameView::boxForScrollControlPaintInvalidation() const
 {
     ASSERT(layoutView());
     return *layoutView();
 }
 
 } // namespace blink