[TEST] Do not add Scrollbar as child of FrameView.

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

 /*
    Copyright (C) 1997 Martin Jones (mjones@kde.org)
              (C) 1998 Waldo Bastian (bastian@kde.org)
              (C) 1998, 1999 Torben Weis (weis@kde.org)
              (C) 1999 Lars Knoll (knoll@kde.org)
              (C) 1999 Antti Koivisto (koivisto@kde.org)
    Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights
    reserved.
 
    This library is free software; you can redistribute it and/or
@@ skipping 1125 matching lines @@
 #endif
 
   ScrollbarMode horizontal_scrollbar_mode_;
   ScrollbarMode vertical_scrollbar_mode_;
 
   bool horizontal_scrollbar_lock_;
   bool vertical_scrollbar_lock_;
 
   ChildrenSet children_;
   PluginsSet plugins_;
+  ScrollbarSet scrollbars_;
 
   ScrollOffset pending_scroll_delta_;
   ScrollOffset scroll_offset_;
   IntSize contents_size_;
 
   bool scrollbars_suppressed_;
 
   bool in_update_scrollbars_;
 
   std::unique_ptr<LayoutAnalyzer> analyzer_;
@@ skipping 110 matching lines @@
                   frameViewBase.IsFrameView());
 DEFINE_TYPE_CASTS(FrameView,
                   ScrollableArea,
                   scrollableArea,
                   scrollableArea->IsFrameView(),
                   scrollableArea.IsFrameView());
 
 }  // namespace blink
 
 #endif  // FrameView_h