MainFrame scrollbars should work with RFV instead of FV

third_party/WebKit/Source/core/paint/ScrollbarManager.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef ScrollbarManager_h
 #define ScrollbarManager_h
 
 #include "core/CoreExport.h"
 #include "platform/scroll/ScrollableArea.h"
 
 namespace blink {
 
 class CORE_EXPORT ScrollbarManager {
   DISALLOW_NEW();
 
   // Helper class to manage the life cycle of Scrollbar objects.
  public:
   ScrollbarManager(ScrollableArea&);
 
+  // TODO(crbug.com/661236): The scroller should be the one that owns this
+  // ScrollbarManager and this setter should be removed.
+  // The scroller that this scrollbar it attached to.
+  void setScroller(ScrollableArea*);
+
   void dispose();
 
   Scrollbar* horizontalScrollbar() const {
     return m_hBarIsAttached ? m_hBar.get() : nullptr;
   }
   Scrollbar* verticalScrollbar() const {
     return m_vBarIsAttached ? m_vBar.get() : nullptr;
   }
   bool hasHorizontalScrollbar() const { return horizontalScrollbar(); }
   bool hasVerticalScrollbar() const { return verticalScrollbar(); }
@@ skipping 17 matching lines @@
   Member<Scrollbar> m_hBar;
   Member<Scrollbar> m_vBar;
 
   unsigned m_hBarIsAttached : 1;
   unsigned m_vBarIsAttached : 1;
 };
 
 }  // namespace blink
 
 #endif  // ScrollbarManager_h